All right. Thank you, ladies and gentlemen. Please be seated. All right. Mr. Deedrick, would you resume the witness stand, please.
Douglas W. Deedrick, the witness on the stand at the time of the noon recess, resumed the stand and testified further as follows:
You are reminded, sir, you are still under oath. And Miss Clark, you may continue with your direct examination.
Thank you, your Honor. Good afternoon.
THE JURY: Good afternoon.
DIRECT EXAMINATION (RESUMED) BY MS. CLARK
Okay. When we last left off you had indicated you--you had finished telling us about how you will mount hairs and fibers on slides.
After you complete the mounting of the hairs and fibers, what do you do with the completed slides?
Well, the slides are placed individually on a slide holder in numerical order. From that position they are taken to a research microscope for examination under a low magnification and then through the whole process.
And were all of these slides prepared in the manner you have described in this case?
Did you mount all of the hairs and fibers that were found in the paper folds on slides?
Well, some of the hairs that were found or fibers that were found were consistent with others that I had mounted from the same material, such as from the gloves. And there were some fibers, animal fibers that were present. I didn't mount those.
Nevertheless, are all of those fibers and hairs maintained, whether they are on slides or not?
And so if anyone wants to reexamine them in the future they can do so, whether in slide or paper?
And were the known standards, that is, the samples taken from people's heads and from various clothes, were they mounted using the same procedure you have just described?
The original known set of hairs was prepared by Susan Brockbank of the Los Angeles Police Department crime laboratory. All of the other known samples that I received later I prepared.
When Susan prepared those slides of their hair standard was she in the same room with you?
I did. I gave her some instruction as well as to how I would like to see the slides prepared.
She initially started using her own just out of habit and we decided and it was more time saving to do them the way that we normally do them.
Well, with hairs it just depends on the racial origin, the length of the hair, the thickness of the hair, the curliness of the hair. It has a lot to do with it. There could be five, there could be three, there could be fifteen. It just depends upon the hair.
Well, if a hair is removed from some debris and it is twenty inches long and it is from an Asian, you know it is going to be a big hair. I might only, you know, mount one hair on that slide because it takes up a lot of the space. You are only given a less than one inch by three inch space to mount that material, but if you have shorter hairs that are, let's say, half an inch long, for instance, from a black individual or from a white individual, you might be able to prepare more. You don't want the slide--the coverslip and the permount to be too thick, otherwise it is kind of like floating around in a submarine trying to figure out where these hairs are. You want to make a pretty flat mount, so it depends on the hair.
Do you--okay. Well, at the time that Susan Brockbank was mounting the known standards on slides, what were you doing?
I was looking through the questioned debris, the questioned material, and preparing slides myself.
What is the possibility of any of her--the known standards she was working on jumping over onto your slide on the other desk?
No, that is not a possibility. The--too much space in between and there are no air currents to speak of in that room.
Well, the room is about probably 12--15-by-15. There are two examiner's positions and in front of--in front of the examiner's positions are the technician positions, so each room will have two examiners, two technicians and there will be microscopes at each location.
So is it common to have two people working on slide mounting at the same time in that room?
There could be four people mounting--working on slide mounting, slide preparation.
Well, once the slides are prepared they are again laid out in numerical order and I follow the process of looking at the questioned material first, I try to look to see what do I find at the crime scene, what do I find on items from the victims, and then I move to the accused or the suspect in the case and then I look at the known standards in that order.
I just want to see first what I have. In the slide preparation, normally the slide preparation goes questioned material first and then known and that is to avoid having the known exposed.
Well, you do everything you do to avoid any possible contamination. You are concerned about that. We know the risk that is involved with contamination, so you take every effort possible to avoid that so that what you are seeing is actually what was on the item.
You see a photograph before you. I would ask, your Honor, that it be marked 462. This will be a series. Could I ask that it be 462-A?
Well, here the examiner is looking at the slide using the stereomicroscope. It may be the first step for some examiners to examine that slide in that way. Low magnification, we start it at about, it could be ten "X" and go up to maybe 40 or 50 times magnification.
Well, you are looking for--if you are looking at hairs, mainly racial characteristics can be distinguished; length, color, shape, contour, appearance of the tip, appearance of the root. It is easier to say in that instance, perhaps, the apparent shape of the hair itself, the three-dimensional shape of the hair, because you are looking at it in three dimensions, but it is just a low screen--low magnification screening tool to look through the hairs to identify which hairs that you may want to look at under higher magnification.
Is it at this point that you determine--is there such a thing not suitable for further analysis or comparison purposes?
Well, there are head hairs, pubic hairs and some facial hairs are routinely the hairs that are compared microscopically. Hairs from the arm, from the leg, body hairs, for instance, for instance, from the trunk, the back, the eyes, eye hairs, eyebrows, eyelashes, these hairs are not routinely compared in forensic laboratories, nor are they compared by us routinely. It may be of some interest in some instances where someone may be hit with like a club, hit in the face, and on the club you find eye hairs that are imbedded in the club, then that takes on a little more significance, but looking at debris found on clothing or from vacuum sweepings from a floor, they probably shouldn't play a very significant role in any hair identification.
So what--what is it that causes you to determine whether a hair is or is not suitable for comparison purposes?
Well, if they fall into the categories of the types of hairs worth comparing, it is just experience and the hair itself. You look at the hair, you determine from experience if it is worth comparing, there is enough of the hair to work with and if it is again from that region. And some hairs are very distinctive. You might not need a whole lot of hair to make a comparison.
Well, there is no set number of characteristics that are needed to make a comparison. That is up to the examiner and the experience of the examiner and how many hairs they have seen, what types of hairs they have seen, what is unusual, what is usual. And based on all that the decision is made to determine--as to whether or not to compare it with a known standard.
Now, the next slide--excuse me--the next photograph that is on the screen now, 462-B, can you tell us what is being depicted in that photograph?
That is just a close-up of the slide. It is difficult to see perhaps by the slide on the stage of the stereo binocular microscope?
Well, here the examiner is sitting at the comparison microscope and that is the main--really one of the main tools of the unit and that is the tool that is used to take a questioned piece of material, like a hair or a fiber, and compare it in the same field of view with the known material. For instance, if a hair were recovered from a weapon or from an item, it would be mounted on a glass microscope slide. Now, that instrument--there are two microscopes there. One microscope would be used for the questioned slide. The other microscope would be used for the slide containing the known hairs from the individual. And by looking through the eyepieces, which he is doing here, those eyepieces will allow you to see both of the layers at the same time. The same type of comparison is done with fibers. You are comparing questioned material, known material in the same field of view. More people are familiar with comparing bullets. I mean, I grew up and that is all I ever saw on TV shows, was comparing scratch marks on bullets to see if this bullet came from this gun and they would line up the striations and you could see them. And the difference here is that the material that we are looking at, we are looking through it and inside of it to look at the characteristic because we are using transmitted light and not reflected light.
Well, I don't necessarily think there is a minimum number of characteristics that one needs for making an identification. You look at everything. You look at all the characteristics that you see, and based upon all of these things that you are looking at, an opinion is reached based on that, not on how many notes you take, not on how many points that you write down in your notes. It is actually based on what you are seeing.
So what component does experience, the number of hairs that you have compared and looked at in your--in your tenure as an examiner, what component does experience in that play in all this?
Well, a good hair examiner has a lot of scope time, has a lot of time looking at hairs. The more things you see, the more value judgments you can make regarding what something is worth. We do this everyday ourselves in your own everyday experiences, and I just do it from a microscopic standpoint. We value things all the time and I place value or importance on certain characteristics that I see under the microscope, so the more time you have, the more decisions you can make that are of value, but still, people that come through the training after a year are still going to be seeing a lot more hairs than what many people would ever look at, and within several years they have a pretty broad base, but I have seen obviously a lot more.
Now, as you examined--you talked about notes, sir, as you examine the slide are you taking notes about what you see?
I take notes on again the questioned items first. I look to determine if there are hairs present, the type of hair, animal, human, race, body area, the condition of the root, approximate length of the hair, how--if the hair had any treatment. I may indicate if it is not suitable for comparison or suitable for comparison and I just move through the material that way from item to item until I get to the known. The known hair slides are examined more carefully at this point because I want to make sure I have a good idea in my mind of the characteristics of this individual. I then can go to the comparison scope and make the comparison. It doesn't--it doesn't take--the comparison scope initially, once you get through to the questioned material, you have a pretty good idea what the hairs of this person look like, what the hairs of this person look like, because they are on their own clothes. When you get to the known hairs, you look at the characteristics and the lights go on, "I have seen that hair before. I have seen those hairs before" and you just go back through the questioned material and compare them side-by-side.
Well, it kind of gives you an idea of what you are looking at through the--through the comparison microscope, and essentially it looks like that first chart you saw with a line drawn down the center and that is the dividing line between your two microscopes. The best possible match, the one you try to really get, is where you have a mirror image set up that the hair on the left, which is here the known hair, and the hair on the right, which is the questioned hair, if you looked at them together, they would appear to be one hair and that is what you try to do when you are trying to determine if a questioned hair looks like the known hairs.
You can see the hair kind of goes outside the circle, but the field of view is a circular field, a white background, and it has a center hairline down the middle which separates your two specimens or your two microscopes.
Now, is everyone's hair the same--for example, my hair, okay, I have--I almost lost it. We have one hair. If I pull out this one hair over here, is it going to look the same as, say, a hair over here, (Indicating)?
Yeah. With most people there is pretty good range. I mean there could be a range from--you might have a dark hair a coarser hair on one side and you might have a finer hair on the other side. That is why we require that--that the Coroner or whoever is collecting the hair samples from the individual take a--pulls from different areas of the head as well as combings, because you have a couple things working here. You have hairs that are actively growing and you have hairs that are ready to fall out and then don't look the same. They look a little different. So I request that we get at least 25 to 30 pulled hairs and then take combings as well, so that you can get a good idea as to the types of hairs, that if they were pulled out, what they would look like, and if they fell out naturally, what they would look like, and use all of these hairs in forming an idea about the characteristics of the known hair.
There is a range of characteristics, sure, and when I look at the individual hairs from a sample, I--I determine what the average hair is. You can do that. You can look at them and say, well, I see hairs that pretty much fall within a pretty narrow range and you are going to have some hairs that are outside on the outside or edge of that range, but you include all of those into the characterization or the analysis or the story line that you are writing on these known hairs. This range of characteristics, though, from my experience, is a much narrower range than what you see out in the population, out in other people.
Well, let me ask you to amplify that a little bit more, because if each of us has a range of characteristics, couldn't a hair from the back of my head match the hair from the front of another juror's head or Mr. Darden's? You know what I mean? If there is a range--I shouldn't bring Mr. Darden into hair discussions. I won't do it any more. You know what I mean. If we all have a range, isn't there going to be an overlap? How can you say that my hair didn't come from someone else?
Well, as I said, there is a range with each person. Everybody has a range of characteristics. Some people have a broad range, some people have a lot of hairs that look very similar to each other. It makes it a little bit easier if they are closer together than if they are far apart, but the overlapping suspects, you might say a hair that you find on one person's head, it may have some similarities to another person's hair. There may be some overlap, but it won't match. I mean, it may look somewhat similar, but it won't exhibit the same microscopic characteristics.
I meant to say they won't exhibit the same microscopic characteristics. That is, they won't look the same.
Now, you mentioned, you know, that my hairs would probably look very similar. You are referring to color treatment, correct?
But even if someone has color treated hair, some kind of treatment with respect to the color, would you still see some kind of a range of characteristics?
Oh, you will, sure, and for instance, some of your hairs may be lighter than others, and they may not have as much pigment. They will take on a much brighter color than a hair that is darker, that has absorbed the same amount of color, so you will see pigment granules, you will see medulla, you will see cuticle, scales, ovoid bodies, you see it all, unless it is so darkly dyed that they are covered up, and that is possible.
So when you mount a known hair standard from a given individual, for example, in this case the Defendant's known sample or Nicole's known sample, could you make any effort to assure that you represent the range of characteristics that you have seen in their sample on the slides?
That--yes, yes, I do. That selection is made as you are taking hairs from the container, the original container, whether it is using a stereomicroscope or using your own eyes to gauge length, thickness, color and a range. I mean, her hairs, for instance, appear to have some highlighting or treatment to them, so and some hairs didn't appear to have too much, so it is just a matter of collecting hairs that--that exhibited all those characteristics.
Well, the first thing you do is you mount up what you think is a range, I mean, a good range, and then you go to your material. You may find a hair, for instance, on an item of clothing from that person and you see some--a lot of similarities with the known that you prepared but maybe something that doesn't quite--it looks a little different. You may have to go back and mount additional hairs from the known sample just so that you can increase that range a little bit. You may see something that may not quite be present and you want to clarify it. You may need to go back and mount more hairs. And once in awhile in a case, it happens all the time, that I would call back out to the contributors or the police department and say I don't think you gave me a good enough known standard or I need hair combings, can I have additional hairs, so that I can make sure that what I'm seeing either looks like it or doesn't look like it. I want to make sure of that before I reach a conclusion that it is a valid association or exclusion.
Now, during the examination of known standards in any case, do you make any effort to see that you can--whether you can distinguish between the known standard, for example, in this case you had the known standard of Ron Goldman and of Nicole Brown, did you make any effort to determine whether you could tell them apart?
This is the first thing you have to do when you are looking at known material, you want to make sure that the people you are going to be comparing the questioned hairs to look different. If they look the same, the conclusions or the strength of the association would be minimized. It could have come from either individual.
Not in case work since I have been working. All the known samples that I have gotten over the years, and there have been quite a few, I have never had a problem being able to distinguish the victims of a case and the suspects of the case and multiple suspects. I've had cases where I've had two or three or 400 known hair samples as elimination or possible suspects to compare with questioned hairs found at a crime scene or on a body of a young child, a victim of a case, and it is a job. One thing you have to do is make sure they all look different and that is--actually it is pretty easy to do.
And you have never had any trouble being able to distinguish between two different people's hair?
Sample are pretty easy to distinguish. You have some problems with identical twins. Identical twins can be real close, especially if they happen to live in the same environment and they share very many common things, because environment, and diet and how much sun they get, how they treat their hair, all of these things add the differences that are often seen between hairs that may be very close microscopically. A person may take--may be an alcoholic. For instance, we had a case once where there were brothers. Their hairs looked very close but one person had--
Let me ask you this: How many known hair samples have you examined in your capacity?
In the course of that experience, sir, have you ever had occasion to examine the hairs of multiple family members?
What was--how did you distinguish--they were the same--what were they? Were they siblings, were they mother and father?
Yes. You can distinguish between them. Sometimes you will have family members that are pretty close, but for the most part you can distinguish between even siblings or family members again because the characteristics that I look at are not based totally on genetics. I mean, we know that even brothers and sisters, unless they are identical twins, I mean, they don't--they are different. I mean, they just look different and their hairs will tend to look different as part of this unique thing that we have as a human beings.
Well, apart from genetics, is there something about the way a person lives that will make their hair distinguishable from another person's hair?
Well, a person that has--doesn't wash their hair very much may have dirt and debris and other material in the hair, in the hair shaft, underneath the cuticle or the scales of the cuticle. A person may pick up head lice, pubic lice. You can see those on the hair shaft. A person may have will a lot of damage to the hair. It is not a clean hair, it is subject to a lot of damage. This might be characteristic of the type of person that he is or she is.
Say, for example, if you got the known standards from two family members whose hair color was the same and were of the same race, would you be able to distinguish between them based on these other characteristics that you are describing?
Well, hair color and race are pretty broad categories. I mean, if you say brown Caucasian as an example, there is a lot of people with brown hair that are white. I mean, just an awful lot, so that is pretty broad categorization. There are other characteristics that you look for besides just color and racial characteristics.
Have you been able to distinguish between the hair of two brown-haired Caucasian people in the past?
You do it all the time, in cases that you get in, as well as the tests that you prepare.
Well, you were mentioning two brothers, one of which was an alcoholic, earlier. Did that--does that show up in the hair?
Habits, alcohol abuse, drug abuse, will affect hair characteristics. There may be characteristics found within the hair shaft that I have seen over the years that--that may be characteristics of that person's habits and sometimes they may be the only characteristics that can be used if they are that close microscopically, but hairs are kind of the dumping ground, all right, kind of the dumping ground of the body.
Well, you say hairs are kind of the dumping ground. Will you tell us what you mean by that?
Well, it is a structure that materials are excreted or secreted in, so that they can leave the body. A person--as an example, a person has been poisoned, and this has been documented in a lot of cases, with arsenic, that by looking at the hair one can determine arsenic is in fact present in the hair. If a person is a drug user, the drugs will be excreted or secreted into the hair shaft and they can be tested that way and it is a test that is more commonly being used for employment type matters, rather than invade the body with taking blood samples--
They take hair samples so it is a structure of the body that helps the body get rid of things.
Now, in this case I believe you indicated that you initially got the known standards of the Defendant, Ron Goldman and Nicole Brown, correct?
And I believe you also testified you were able to distinguish each of their hairs from each other?
Did each of the individuals--for example, did Ron Goldman's hair display distinctive characteristics?
Okay. With respect--start with the Defendant first. Did you find--with respect to those distinctive characteristics, at the FBI do you maintain reference samples, photographs of hairs from people of various racial groups?
Well, no. Well, I photographed them. Those were hairs of different black individuals, blacks from this country and from Africa.
Well, these are hairs that were taken just at random from samples from individuals that were in the reference collection. Some--there is one there from a bushman from Africa, one from a Somali warrior, a couple of them in individuals that work in the laboratory. I think there is a blue hair there I believe is one of them, that is treatment. She is a clerk typist in the unit. There is another one that has a red coloration to it. Again I don't recall what type of treatment that was. Mahogany rinse or something like that. But the other hairs just represent some--some randomness, some random variation that is exhibited between different individuals to show you that the hairs do differ microscopically.
Okay. Before we move on to discuss this, let me ask you just a couple more questions. You indicated that the Defendant's hair was distinctive?
Well, it was very light-colored. It had very light pigmentation, prominent one-sided pigmentation, which was prominent in many of the hairs in the sample. There was a number of other characteristics as well, I have them jotted down in my notes, but I felt that those hairs were very distinctive, easy to select.
All right. Now, you indicated that with respect to Nicole Brown and Ron Goldman you also found distinctive characteristics and here we have the board 465. Can you tell us what you are showing us in this--in these 16 different photographs?
Well, there is a couple things I believe in this chart, trying to show that there is a variation or randomness to the color, to the pigmentation, distribution, to medullation or the medulla that you see running down. Some of the hairs have them; some don't. You may find hairs that don't have a medulla and others that do. Again it just shows some of the variation. The three pictures on the right I had to bring in, they are my daughters' hairs, on the right second one, third one and fourth one, starting from the oldest, to the youngest.
Okay. This is my 17-year old's hair, this is my 13-year old and she was a little upset because her hairs have some damage to it.
She didn't want them on TV and the youngest here has the darker hair of the--of the three. Again trying to show that there is some variation even within a family that they will exhibit different characteristics.
Thank you. All right. So you indicated that you examined questioned hairs and then you examine the known and then you go to the comparison process?
And you indicated to us the use of the comparison microscope. Let me ask you this: When you compare the questioned hairs--the questioned hairs that are recovered from evidence at a crime scene to the known hairs of an individual that were collected, would you--what would you say if only one hair from the known standard exhibited the same microscopic characteristics as the questioned hair?
Umm, that is a tough one. It depends upon the hair, how many hairs were recovered, where it was recovered. It may have something to do with whether or not it might be reported. If a hair is on the outer edge of the range, a lot of time those are just thrown out. You don't consider them as a potential. And it is just logic and common sense here, what would you expect to see if this guy shed hairs at the crime scene. Well, would he lose hairs like most of his hairs? He won't lose maybe--just strange that he happened to lose one that looks kind of like one of the weird hairs in his head. I would throw it out. I would rather throw him out and not involve him at all in that type of examination.
In forming your conclusions--in forming your conclusions how do you--do you have some kind of standard that you go by in terms of trying to benefit the suspect?
Well, it is objectivity, impartiality. You don't get involved with the case. You try to report out truthfully what you see based upon the observations you make, put no concern on the outcome. And it is normally a default mechanism built in. Even if there is any question, you throw it out. You don't try to make a match. It either matches--
Yes. Ladies and gentlemen, you are to disregard the term "Match" in this context.
KEY QUOTEI have to apologize because some of that comes out naturally, but if it exhibits the same microscopic characteristics, you call it that way. If it--if there is some differences and you can't account for them, you throw it out.
All right. So for example--well, strike that. We were talking about same microscopic characteristics and when you will form a conclusion, but let me ask you this, sir: Can you say that the hair--that a hair found at a crime scene, even though it exhibits the same microscopic characteristics as the hair taken from a suspect, even though you say that, can you say that it could only have come from this person and no other in the world?
No, no. The--we do not say with absolute certainly that a hair came from a particular person no matter where the hair is found.
KEY QUOTEAre there databases that can tell you which source of the population could have been the source of a particular questioned hair?
When you say that you don't say that, you don't say that a hair could only have come from one person and no other, why is that?
Well, because it--you can see that in some individuals that there are hairs that can be--they can look very similar to another individual, so that in that instance, just because it happens, you can't make a blanket statement and say that it--that it is a positive form of identification. If it happens once, the it happens twice, you cannot say absolutely and we don't say that. Every report that we send out has a statement in it to that effect.
Now, is the microscope, is use of the microscope to perform the examinations considered to be the best method of comparing hairs in a forensic community at this time?
Is there any instrumental means of comparison currently recognized as reliable that have gained acceptance in the scientific community, other than microscopic comparison?
There have been other techniques, other instrumental methods that have been used, none considered to be useful to individualize hairs.
There are naturally occurring fibers such as from an animal. Woolen fibers is a good example. Cotton fibers that come from plants, plants provide textile fibers, and also there are man-made fibers and there are some others, but man made and naturally occurring are the two main groups.
We have a chart here, your Honor, it is on the screen. Ask that it be marked People's 466.
On the upper right-hand portion of the chart you see what is depicted as a cotton fiber and it is probably the most common plant fiber that we wear. Cotton is used for a lot of other things besides wearing, but it is the most common fiber. It comes from a seed bowl, it is a seed fiber. The fiber beneath is a woolen fiber. It is an example of a wool fiber taken from a sheep. Woolen fibers could come from other types of animals as well. It doesn't have to come from a sheep, it could come from a goat. For example, camel hair, another one, cashmere goat is a good example. It is just an example of an animal fiber.
That is an artist depiction of it. Yes, it can. You can see the scales on the outermost portion of the hair. Woolen fibers are hairs, just animal hairs. They look differently microscopically. And some woolen fibers are very fine, not a lot of scale protrusion, they are comfortable to wear, that is what we like to wear. Those woolen fibers that are coarse, that are rough, you might be walking on them, they are not as expensive so we walk on them, but you wouldn't want to wear them.
Well, the manmade fiber--it might be a little difficult to pick out here on the right--I mean, the upper left you see what looks like a longitudinal view. If you looked at the fiber underneath the microscope and the borders on the top and the bottom are the borders of the fiber, all right, and it is just cut off at the end. It has in it a number of structures that might be found. Delustering particles may be added to the fiber to take away the shininess of it. It is just a pigment that is added to the fiber when it is produced. They may also have voids or just large spaces with nothing in them or there may have pigment in them, so it is just an example of what you might see in a manmade fiber.
Well, shape and cross-section are an identifying characteristic, especially of manmade fibers, because the industry decides and produces their fibers for specific end uses. The carpets that you work on may have a much different shape and size or they would, than--than you are--the clothing that you wear on your body. You wouldn't be wearing a rug around, nor would you walk on lingerie, just not that way. There is a design and a purpose for each of the fibers that are produced and certain fiber types have certain shapes and that is depicted there.
So does that chart kind of explain to us what you can tell from the microscopic examination of fibers?
Well, that is kind of the first thing, right, that has--that you can look at and see right off with a manmade fiber or a natural fiber.
Just like that first determination with hairs, is it plant, is it animal, is it manmade.
Your Honor, I have here a chart that is marked--entitled "Cotton fibers." I would ask that it be marked 467.
What I have done here is try to give you an idea of what can happen to cotton fibers that you might wear or you may encounter. Cotton fibers, they are pretty common. I mean, five billion pounds of cotton fibers every year just here in the United States. They go to a lot of different--a lot of different sources. They may go into clothing, draperies, upholstery. There is a lot of end uses for cotton, but the distinguishing features of cotton can be seen in the color, whereas a fiber that is uniformly colored would look different than a cotton fiber that had color at specific intervals or different portions of the fiber. The surface color that is seen in this particular cotton fiber would be characteristic of a printed fabric where the color is added to the surface of the fabric after it is produced. Uniform color might be made or produced when the yarns are coming off, after the yarns have been spun and the whole yarn has dyed. The degree of twist is something that is compared. There is a gray, greige, fiber like a cotton ball. You may see this particular unfinished fiber in blue jeans is a good example. A fiber that is more finished, that has been through a little bit more processing, would take a little bit of the twist out. You might find that in a shirt or a blouse. Mercerized cotton has been treated differently. You find mercerized cotton in threads. It doesn't have very much of these what are called convolutions or twists, back and forth twists that is commonly found in cotton fibers.
Can you tell us--first of all, you told us about the cotton fibers. Now, is this chart about manmade fibers?
Can you explain to us starting wherever you want? I see the one, the title up to the upper left is "Cellulosic." What does that mean?
Well, cellulosic refers to the origin, that is, wood pulp, cotton linters, something that has cellulose or material that is natural as a substrate, as a base material. It is a starting material that you work with.
Some of the first manmade fibers that were produced were cellulosic in nature. That is, they started with something that was naturally occurring. They put some chemicals together and they extruded it into a fiber shape.
When manmade fibers are produced they have to start with some beginning substance. Some start with a cellulose-based substance. Others start with other chemicals and perhaps even like a plastic chip. They felt the chip and then they make fibers out of it. But from this beginning solution it is forced under pressure out of what's called a spinnerette. Looks like a shower head and this--the shape of each one of these little holes and the possessing itself has something to do with this cross-section that you see, the shape of the fiber that comes out of it. Dry spinning, it is forced out in air. Rayon, which is a cellulosic, acetate and triacetate on these particular shapes. And as they dry, they crimp and looks--looks like you have a striated or streaky fiber as it is laying on a microscope slide. With non-cellulosic, we see that in nylon polyester, acrylic, modacetate, olefin. Olefin is polypropylene, polyethylene substance with maybe either melt spun or webbed spun that may be extruded or pushed out of this spinnerette into a liquid bath or it may be again in air and in hardness. With melt spin you start out with plastic chips in a big vat and they are melted and into this vat you can add color, you can add delustering, you can add a lot of different things, and then when the fibers come out, these particular fibers, especially nylons and polyesters and olefins, they are the types that end up on carpets and many of the fabrics that you wear. You can really control the shapes and the shapes have a lot to do with how long they last, where they are intended to go, what is going to happen to this fiber, how it is going to feel if you wear it. So these are just examples of some of them. Some of these they don't even make any more, some are still in production. This particular fiber, as an example, it looks like a dice. If you look at a cross-section of it, it has four holes that run right down the center of it, and the purpose, I'm not sure. Maybe to make it lighter, I don't know. But an end use, a lot of these things are included into the factors that make up the fiber you see. This one has five rows running down. This is called a tri-lobal fiber. It has three lobes. This particular one has a hole down the center of it. That is quite unusual. These particular tri-lobal fibers have different shapes and sizes of the lobes, an identifying characteristic or that particular fiber or fabric that you are comparing. Acrylic fibers may end up being shaped. This particular fiber is irregular or round. It looks like it has about six lobes. The bottom of the chart gives you an example here and this has to do with why I'm here, and that is, the types of fabrics that end up on individuals involved in crimes. Yarn types could be two types in particular, a staple yarn and a filament yarn. Staple yarns are made up of a lot of small fibers that are spun together very tight. They tend to shed a little bit more because there is a lot of loose little fibers, whereas a filament yarn, whereas in a nylon jacket, long filaments of indeterminate length, they would have to be damaged for them to be shed. They don't shed that easily, but all of these end up into a fabric, whether it is a knitted fabric or a woven fabric or a banded had fabric. And there are several different types. Most types that you encounter would be knitted fabrics and woven fabrics.
Is there a difference in the shedding properties of fabrics that are ever a staple or filament type?
There is a difference, yes. Staple fibers--staple yarns and staple fabrics tend to shed more and also they tend to hang onto things more.
Just by their nature. Just the surface characteristics of the fabric are such. The more worn the fabric, for instance, you may wear away a lot of the loose fiber ends that are present. This particular fabric wouldn't hang onto things that well, whereas a new fabric that has a lot of loose yarn still on the fabric may hang onto something and keep the fibers longer. A bulky sweater, a bull ski sweater will shed and it picks up a lot of stuff just by its nature.
Well, filament fabrics--you may find a filament fabric that is a very slick fabric. A nylon jacket would be a good example. You may find filament fabrics in lingerie. Any type of filament fabric that is made up of this particular type of yarn wouldn't shed very easily, it would hold onto things very easily. It is something to consider when you are looking at evidence. You kind of expect to see certain things based on the fabric that you are handling.
You know, you saw Nicole Brown's--the dress that she was wearing on June the 12th that she was found in. You examined that fabric, a known portion of that dress?
I don't recall on that. It may have been filament. I'm not sure on that, though.
Okay. We will get back to that. You indicated earlier that you can examine fibers and you talked about mounting. Is the mounting process for fibers the same as the mounting process for hairs, on slides, that is?
It is pretty much the same, the same techniques, same mounting materials, precautions, probably take a little more precaution with fibers because of their nature.
They are smaller and you can lose them if you are not careful. They tend to be--they tend to float around a little bit more.
Well, the exam is conducted in a similar way in the beginning as with hairs. That is, you look at it with a stereomicroscope, look at it with a research microscope. You may compare it with a comparison microscope to see if the questioned material found on the victim's clothes look likes the fibers from the fabric of the suspect in the case. And once--once the determination is made that they either look the same, or if they look the same, then you go to the next step, and there are several steps beyond that which help to confirm this eyeball association that you are making.
Well, let's assume for a moment that you have compared a questioned fiber from the crime scene, say, a fiber on a victim's shirt to clothing that the perpetrator was wearing when he was arrested, and let's say that you determined that they exhibit the same microscopic characteristics. Is that where you stop?
Are they the same with respect to whether the fibers are manmade or natural fibers?
No, no. They will differ. Manmade fibers can--can use additional tests for confirming.
Then let's start with the natural fibers, naturally-occurring ones. Let me just back up and ask you this: You said there are additional steps that can be taken or tests that can be done on manmade fibers?
So in other words, would it be fair to say that you can do a certain number of tests beyond the microscopic examination on manmade fibers and natural fibers and then you can do more than that if they are manmade?
Let me just ask you, whether the fibers are manmade or natural, after the microscopic comparison reveals the same or similar characteristics, what steps do you take with respect to manmade or natural?
Almost all of the steps beyond that point are still microscopic, but they are different instruments, different types of microscopes that can be used to confirm an identification of the fiber type and also to compare certain properties of the fiber. You might--as an example, a polarizing microscope might be the second step after a comparison is made. A polarizing microscope is one that is designed specifically to allow you to look at polarized light and how it affects the--the synthetic fiber that you are looking at. And a polarizing microscope is--it is not too simple, but it is simple to understand when you think in terms of sunglasses. If you have polarizing sunglasses, you know how when you wear them they tend to cut the glare. They do this because they are designed to let light only enter your eye in one direction. That the light coming and scattering in all directions hits your eye. It is like venetian blind, it only let's the light come through in one direction. You put a polarizer on the light source of a microscope and you can control which direction you let the light hit the fiber with. By placing another polarizer above it, which is called an analyzer, which he essentially the same thing, the polarizing filter, and by adjusting the orientation of these you can actually cross them so that no light comes through when you insert that fiber in between. The fiber interferes with that light and you will see color and it is called interference colors, and by examining the interference colors and by doing some measurements with some instruments that can be added to it, you can identify the generic group of the fibers. Is that a nylon fiber or it is a polyester fiber? These can be done with that instrument and you can compare them. You can do comparison of interference colors with questioned and known.
For example, if you have manmade--no, not fibers. After do you the microscopic comparison--the straight microscopic comparison, what would be the next thing that you might do to compare questioned and known natural fibers?
Once a determination is made as an example of, let's say, a cotton fiber, looks the same under the comparison microscope, the next step would be to take it to what's called a microspectrophotometer. That is a big word. I don't know if we have a picture of that.
The microspectrophotometer is like a regular microscope that has a photometer head, it has a meter that sets on the top of it. As an example, here you can see I'm looking through the microscope. Above that white area, just above it is measuring the light that is passing through the fiber and it can measure light at specific wavelengths, so that if the color that is added to the cotton fiber, it comes--let's say, maybe three different colors are added to the fiber to give it the color that you see normally in daylight, that this instrument can show that these different components will interact with the light at specific wavelengths and it will present you with an absorption chart which shows where the colors are and where they are absorbing. Our eyes see one color. The instrument actually allows you to see where these components are in the visible spectrum.
And the chart you are referring to, is that actually shown on the screen of the monitor in this photograph?
It is hard to see, but yes, that is the--what you get from looking at the fiber.
Okay. Now, we are showing you a chart. I would ask that it be marked People's 469-A, your Honor.
Well, this chart here shows you two brown carpet fibers that were examined under the same conditions. The chart that was prepared of one differs from the other. That is because they are different, different brown colors, just to show you when they don't look the same.
And is that a sample of a chart that would be produced by the microspectrophotometer?
I have heard that before, yes. It is essentially the spectral fingerprint or representation of the colors that go into the fiber, the dye components.
Well, the color range that we are familiar with. Fingerprint in a sense that it identifies the components of a particular fiber by the color components.
Mr. Deedrick what would you say about the results on this chart with respect to whether or not the blue cotton fibers match?
With respect to whether or not the--with respect to the results on this chart, can you tell us whether or not you would draw the conclusion, based on these results, that these fibers had the same origin?
MR. DEEDRICK: The chart that you see indicates that the colors are different, that in fact one fiber, if they--if the question is did the one fiber come from the same source based on this spectral result, they did not. (Discussion held off the record between the Deputy District Attorneys.)
You look at the absorption peaks, absorption and transmission of that particular color in specific wavelengths.
Anybody want to stand up and take a stretch while we are at this point? Well, I'm going to stand and take a stretch.
All right. Is this another chart that would be generated by the microspectrophotometer?
Can you tell us, with respect to the results depicted in this chart, whether or not you would conclude that the two fibers measured by that instrument would be determined to have had the same origin?
When one fiber was tested it produced a curve like you see, let's say the top curve. The second fiber produced the bottom curve. And what an examiner looks for is to see if there is conformity at the specific absorption peaks and transmission peaks. In this particular case they do conform. This particular test was taken from the same fabric which shows you another thing, that they don't have to lay one right on top of the other, that they do--they will absorb dye differently. So you have to look at how the curves appear, not if they lay on top of one another.
Okay. So in this case the two blue fibers, they were actually picked off from the same material?
And if we measured their yarn and you would try to follow the same peaks and valleys and that is how you would determine whether or not it had the same origin?
Is there anything that will produce a different peak, any kind of added--for example--if a piece of yarn--if you have two pieces of yarn from the same ball, the same origin, one piece has a little bit of blood on it, the other one doesn't, is that going to cause some difference in the result on a chart like this?
It will. It will pick up the color. Just not knowing any difference, it will absorb in that particular region of the spectrum.
Is there any way to account for that in determining whether or not two fibers could have had the same origin so that you don't improperly exclude it because of the blood?
Well, you could--you could do a test sample of the fabric and add blood to it to see the effect of blood to that particular known sample, or you could clean off the blood and see it without the blood present. The blood peak is pretty easy to see, and once you see it with the microspectrophotometer on the chart, you can infer that.
Well, it--in criminal cases often involve bloodshed and clothing, fibers, often pick up blood. The questioned fibers that you look at may have--may have blood on them. The known standards that are taken routinely are not--you don't try to take known standards from the bloody area. You try to take it from a clean area and you may have to take it from the bloody area just to show the comparison, but we are talking a real small piece of fiber, though, on the board, and we are talking about a very small area of the fiber that you are actually testing, but you can pick up an absorption in that particular--if it has blood on it.
All right. So let's assume for a moment that in your comparison of the natural fibers you have done the comparison on the comparison scope and they seem to have the same characteristics and you go to the microspectrophotometer and you produce wavelengths that have the same characteristics, peaks and valleys. Is there some further step you can take?
Yes, it is. It is again a comparison microscope which has fluorescent tubes in the uppermost portion of it and they can be altered. A specific type of light is reflected off of the surface of the fiber, and if the fiber has fluorescent qualities, it will absorb certain wavelengths and will emit a longer wavelength. It appears to be a different color to the eye under different lighting conditions, we use ultraviolet light, blue light and green light, and comparison is made between the questioned and the known the same way. If the question fiber and the known fiber fluoresce the same and they are the same in all the other tests that are conducted, it is just another confirmation. Where you might have problems is you go through the steps and you find that they are all very similar but the fluorescence is wrong. That might be a way to eliminate that fiber as possibly coming from a particular garment.
Okay. So if you are trying to determine whether or not a questioned fiber and a known fiber could have had the same origin when you subject them to, say, did you say green light, for example, you might use--
--a green light under the fluorescent microscope, they should fluoresce the same way?
They should, right. If they fluoresce, they should fluoresce the same. The color that you are looking at visually should be the same.
Okay. If one does--if the questioned fiber fluoresces under the green light and the known fiber does not fluoresce under the green light, what conclusion, if any, would you draw?
Well, there is two possible: One, that they came from different fabrics. And two, something happened to the one that the--it didn't happen--for instance, you may have some time factor. You may have the fiber laying out in the sunlight for a long time and losing its fluorescent qualities or ability. It gets faded. It leaches out--leaches out whatever ability that fiber had to fluoresce. The known fiber was retained and wasn't affected the same way, you might find that the questioned fiber doesn't fluoresce, yet the known fabric still does, so then it is a matter of maybe doing some tests, taking some of the known fibers, heating them out in the sun for awhile, the same period of time, and then seeing if they act the same way.
So would you ever call an exclusion, that is, determined that a questioned fiber and known fiber could not have the had the same source based solely on what you see under the fluorescent microscope?
You could. It depends on the circumstances, the historical information that might be available about a fabric. I have done it. I have done it before.
So far the steps that we have gone through, are these steps that you can do to both manmade and natural fibers?
After the fluorescent microscope stage is there some further step that you do on natural fibers?
There is other tests that could you use, sure. You could strip the die using thin layer chromatography, even using dye separation. There are a number of tests that could be use.
Some labs they are. He don't do thin layer chromatography in our lab. It is a destructive technique. Some instances we might, depending on the circumstances. You have to have a lot of known standard to work with. That is, enough so you can determine the system that you might want to use because you have to take the dye out of the fiber and then you have to see how it can separate on a chromatographic plate. So you need enough to work with to experiment to see if you only have one fiber found on the victim's clothes, but you have a lot of fibers from the suspect, you want to make sure that if you are going to do anything to this questioned fiber that you better know the results you might expect to get, because once you take the dye out of the fiber, you have destroyed it.
The processes that you have outlined for us so far, any of these deinstructive processes?
So that when you complete all of the steps that you use at the FBI is the hair or fiber intact as you found it?
All right. Now, for manmade fibers can you go farther than fluorescent microscope and thin layer chromotography?
So after all the steps you have gone through, everything looks the same and you come to FTIR--what does that stand for?
I will probably really--it is Fourier Transfer Infrared Spectroscopy. Fourier, spelled F-O-U-R-I-E-R, and I apologize to these people who know more about it.
The instrument that we have has a microscope attachment. A small portion of the fiber is flattened, actually a roller is applied to it to make a thin layer of the fiber. And then passing infrared light through it, it will--it will again absorb and it will affect--it will affect based on the polymer that is in that particular fiber. The molecules that make up the fiber interact with the infrared light and they start shaking and vibrating in all directions and this shaking and vibrating allows the chart to be prepared and this chart will identify the polymer and also can be useful for a comparison.
Okay. Let's--let's pull up the chart and tell us how it can be useful for a comparison, as well as the identification of a polymer. Actually, before we do all that, what is a polymer?
A polymer? It is a--it could be a manmade fiber as an example. It is a long chain of synthetic material, manmade material, made up of a lot of smaller components. It could be called monomers and a lot of them are poly, so it is a polymer. You might start with some small building block and you make a lot of it, a long chain of it, and that is what makes up a particular fiber. Different--different building blocks make up different materials.
So when you say identification of the polymer, you are telling us that when you identify the polymer you are identifying whether the manmade fiber is rayon or nylon, that sort of thing?
Or nylon 6 or nylon 66 or nylon 11. It depends on the type. There are different types of nylons and there are different types of acrylics and there is different types of polyesters. And this instrument can be a little bit more specific. Whereas I can say it appears to be a nylon fiber based on my tests, this could tell me it is a nylon 66 fiber.
Well, then again you are kind of going into the field of ftir that perhaps I'm not most expert at, but it gives a chart of the reaction of the infrared light through that material.
Well, this particular--this particular chart is indicative of a nylon 66 chart and that is based upon a comparison with a database of spectra of nylons. By comparing that spectra that is produced with known standards, that particular polymer can be identified. It is useful also from the standpoint of comparison because dye components, coloration, anything that is added to the fiber will also interact with the infrared radiation that is hitting the particular fiber so that you may have dye peaks that may not be characteristic of an undyed fiber, so it can be useful for comparison as well, besides identification.
Yes, the position of the peaks in relationship to each other, questioned and known.
I think you spoke earlier about the cross-section of a fiber on one of the charts. Is that something that you routinely compare, the cross-sections of fibers?
Well, a cross-section is how it looks. If you look down the end of it, it could be lopped off a tree, you know, it is round, or you lop off a fiber, you know what shape it is.
Sometimes you can. Sometimes you can. The more intricate the cross-section or the more unusual the cross-section may require using a sectioning technique that is a manual technique which you can do right in the unit, or you might take it to the scanning electron microscope and this is a technique that can be used there which will allow a different type of section and a different type of look.
Okay. On the chart concerning fibers that we saw before, you pointed out the tri-lobal look and then had one that had the four holes in it like a die--like dice?
What is the scanning electron microscope that you said could be used in connection with the examination of cross-sections?
The scanning electron microscope actually passes a beam of electrons striking the surface of a material and then it is depicted. The material, the reflection of that--of those electrons onto a detector will give you an image, a three-dimensional image of what you are looking at.
Did you have--did you furnish some photographs to be shown to the jury of the example of the kind of photographs that are taken by the scanning electron microscope?
No, no. The--we do not say with absolute certainly that a hair came from a particular person no matter where the hair is found.
It doesn't--it doesn't take--the comparison scope initially, once you get through to the questioned material, you have a pretty good idea what the hairs of this person look like... When you get to the known hairs, you look at the characteristics and the lights go on, 'I have seen that hair before. I have seen those hairs before.'
Ladies and gentlemen, you are to disregard the use of the term 'Match.'
Hairs are kind of the dumping ground, all right, kind of the dumping ground of the body.
I shouldn't bring Mr. Darden into hair discussions. I won't do it any more.