All right. Thank you, ladies and gentlemen. The record should reflect that we have now been rejoined by all the members of our jury panel. Mr. Gregory Matheson is again on the witness stand undergoing direct examination by Mr. Goldberg. And Mr. Goldberg, you may continue.
Mr. Matheson, yesterday you were testifying about using a process called electrophoresis?
Electrophoresis is a technique that is used to identify the different enzyme types, these polymorphic enzymes that we were talking about before.
Well, in the case of the type of testing we are talking about here it is not used in the ABO, it is used in enzymes, and it is used in other purposes, too.
Well, like in the ABO system where you have different types that can be identified in these enzymes, they also exist in different types. An example being a PGM that I mentioned earlier, in its simple form it is a type 1 a type 2-1 and a 2. Each of these types differ slightly in their structure, in their charge. That is one of the ways we use to tell them apart. The electrophoretic technique involves taking a glass plate that is approximately about eight inches square, pouring what is called an agarose gel on it, which is kind of like a Jell-O like substance on the top of it, placing the samples on--you take small portions of the blood or the cloth, absorb it onto threads, insert it down into the gel all in a line.
this then is placed on that cooling bath and electricity is allowed to run through it from one side to the other in one direction and this basically kind of pushes the enzymes along and they travel at different rates based on this charge that is on them, the slight differences. After a predetermined amount of time, you stop that electrical process and put chemicals on it over the top that work with the enzyme so you can see where the bands lined up. In most of the systems you identify the type by the quantity and location of these bands on the gel and in some systems you do it as far as location and quantity along with the intensity or the darkness or brightness of each of the individual bands.
So after running this electrophoresis gel, you get some kind of a banding pattern?
Well, each different type of an enzyme will give a unique banding pattern so you are then able to interpret it. You don't just do it from memory, though. On each of those gels or each of the plates that I was talking about, which with the system that we have set up we can run up to twelve samples on it, out of those twelve samples three or four of them may be a control or known sample of all the different types that are present in the system. So you would have a situation where would you have a sample, a control, a couple samples and a control. That way you can make direct comparisons between your unknown sample and your known types and make the call and determine what type it is.
Your Honor, at this time I would like to mark as People's next in order, it is 215 for identification, another board entitled "Evidence testing demonstration."
Sir, directing your attention to this exhibit 215 for identification, the first photograph, photograph no. 1, "Door to serology." May I have that on the elmo? What does that photograph depict?
It depicts the door into the serology lab from that hallway from the chart that kind of goes around in a square around the laboratory itself. It is always--when you are talking about windows before, although there are no windows to the outside, each of the laboratories has a couple of windows that look from the lab itself into the hallway.
Now, directing your attention to cell no. 2 on this demonstration exhibit, what does that show?
That is a photograph that is taken if you were to walk just inside the door shown in cell 1 and turn to the left. It looks down through the serology laboratory. What you see on the left is a personal work bench area or one of the areas of one of our criminalists. To the right you can just barely make out a little bit of a layout table, and then farther back on the right is one of our group or analytical areas.
And can you see where the electrophoresis machines are kept in this particular photograph?
Well, by using the pointer toward the right of the photograph you can see these reddish ends, those are all the electrophoresis cooling plates or cooling tanks that I talked about earlier.
Now, directing your attention to cell no. 3 on this exhibit, what does this show?
Okay. As I described in the process before, in the electrophoresis, you pour a gel on a plate that is about eight inches square, something like that. That is depicted in the picture, one of those plates. The gel is on the glass part there that you can--actually can't see the gel because it is clear. Then there is a row of slits that are put in it where the samples are introduced. It is called loading the gel. Each one of these red marks that you see is indicative of either an unknown sample or a control or known sample.
And going through the four items here, can you tell us where the unknown samples would be, as opposed to the known sample?
Well, my practice in running a gel is I put an unknown in the first, a known sample in the second, unknown in the third and the fourth and then a known one would go in the fifth spot.
Anytime I refer to an unknown sample, it is an evidence sample. We don't know the results of it at this point.
The known is a portion of blood where we know the source of that blood and we have already characterized and known what the types of them are.
Okay. The plate then is laid in this--or the fourth cell here that is marked "Electrophoresis." The white part in between the two red ends is a cooling plate. There is a bath or a mechanism not too far away from here which has a refrigerant in it which lowers the temperature of the water. The water is then circulated back and forth through these plates so that the electrophoresis gel is kept at a low temperature so it is laid on top of that.
And finally, if we look at the fifth gel where it says "Run gel," what is this showing?
Okay. This shows a couple of different tanks side-by-side. The right one here has a gel laying on the cooling bath to actually run the electrophoresis system. There is white what are filter papers called wicks on either side of it. They are in a tank that has a buffer solution. The wicks are laid across the edges of the gel on both sides and then there is cords that go up to the power supply located toward the top of the picture and electricity is run through the buffer, through the wicks, across the gel and then back into the power supply. They have to be kept cold because most of our systems in this type run at approximately 350, 400 volts and that would--if there wasn't a cooling system, it would actually heat the gels up and dry them out and the process wouldn't work.
Now, if this were a real case and this evidence were to be run, what would you have to do after the item had been--the gel had been placed on the plate as depicted in cell 5?
Right. Like I mentioned, the wicks would have to be laid from the tanks on the edges of the gel. You close this lid because you don't want to come in contact with the voltage running through it, and the wires to the back of the unit are placed into the power supply which is above it.
Now, if we can go back to cell no. 4 for a second. Can you point out where it that is the samples are that have been loaded onto the gel in this photograph?
They are a little tough to see, but you see that the gel is being held up, the gel is on a piece of glass being held up on its side, and the reddish spots that show up about two inches or so from the bottom of the gel.
And can you tell us using this photograph when the machine is hooked up and the electricity is actually running through it, can you describe for us what happens?
Well, as far as like I mentioned in the description before, the current runs through it, there is a positive side and a negative side, and it runs from the positive to--correction * the negative side and a positive side. It runs from the negative to the positive side and the enzymes that are present in there, they are such that they--they move along through the gel at a slightly different rate, depending on the structure of them, and the structure is what determines the type.
So which way do they move? As it is placed on the machine this way would they go from his right hand to his left hand or the other way?
Well, it depends on the system. This system here that is setting up appears to be a PGM subtype system that we use and it would be running from the right to the left.
And when they run from the right to the left, can you actually see some sort of a banding pattern with your naked eye after it is finished?
After the run time you remove this gel from the cooling plate and you have prepared what are called development chemicals, and they are optimized for a particular enzyme system. The chemicals contain or the solution contains chemicals that react with the enzyme so that we can see them. Normally, if it is a visible thing that you can see with your eye in white light, it is a dark bluish almost black type of band formed. There is another type that react with what are called florescent chemicals and you have to look at them under ultraviolet light.
After the plate is run and the development chemicals are put on, is something done to preserve that plate?
Yes. The plate itself is not preserved; however, the results are photographed. They are actually photographed several times throughout the development process. It doesn't just pop up all at once. It slowly becomes visible in most of the systems and you take pictures along the way.
How complex is this technique--how complex was this for you to learn how to do this technique?
Well, it is not a terribly easy technique, but it also isn't difficult. I was able to--I mentioned yesterday a course that I took back at the FBI academy which lasted about two weeks in duration. During that two weeks I went into it with having used this technique maybe less than half a dozen times or so just practicing in the laboratory. And within the two weeks I became fairly proficient at running samples.
Now--thank you. You said it was possible to calculate the frequencies of people that have different genetic markers that you have tested. Is there a rule known as the product rule that you apply in doing this?
What that is, is it allows you to determine the types of different markers you identify and it is possible, just through statistics, you know that going back to the ABO blood typing system that a certain percentage of the population is a type A, a certain percentage B and so this is also true of the different enzymes that I am talking about. So once you have identified the types, say, in two different markers, ABO blood system and maybe this PGM system that we have talked about, you can multiply together the percentages of each of the types that are present and come out with a smaller percentage of the population that has those two types together.
Well, starting with the ABO system, about roughly half of the population is a type O or about fifty percent of the population. If it was the only test that was available to us, we can analyze a blood stain and determine that it is a type O and the best information out of that is that half the people in this room could have contributed that blood stain. Well, then we go ahead and run one of these additional genetic markers. Let's say out of that we identify a type that also exists in fifty percent of the population. Well, now we have two pieces of information. You can multiply those two together and now you know that that stain down there that is an ABO type O plus this other marker exists in about 25 percent of the population or about one out of every four people, rather than one out of every two. With each additional marker you add you keep multiplying that percentage and the number of possible people that could have left the stain gets smaller and smaller.
So if you had a third marker in your hypothetical that was also fifty percent, you would multiply 25 times 50 for 12 and a half?
Your Honor, I'm going to object and move to strike that last answer as being lack of foundation and I think we need to approach on this.
Yes, that's correct. With each additional marker, if it was half, you would keep cutting the number in half. It would go to one in four to one in eight to one in sixteen and so on.
And is this use of the product rule in calculating the percentage of the population that has a given set of genetic markers one that is accepted in the forensic science community?
If you know the product rule in terms of applying it in this context with ABO systems and the other genetic markers?
And is that pretty standard throughout the forensic community, that those are the systems that are used?
With respect to the systems that are used in your laboratory, how long, if you know, has the product rule been used to calculate the frequencies of those systems together with ABO?
Well, it has been used in our laboratory since I started, which was in 1978, and I believe the markers have been available, they have been used with each new one as it is developed.
Okay. Now, in terms of the conventional serology, and the electrophoresis tests that you have been discussing this morning, is there a problem with cross-contamination between the sample as you are doing the test?
If I understand what you are saying, I mean you always want to be careful that you don't allow one item to come in contact with another one so that you have the potential of transferring information between the two.
How much of a sample do you need in order to be able to test an item of evidence using electrophoresis?
For the systems that we use, we need a sample that has, you know, some color to it, you know, towards a pale to dark red. Approximately a quarter inch long thread size is about the sample you need to get a good result.
If we were to define contamination as being introducing something onto a piece of biological evidence that was to cause the evidence to be mistyped, what would you need to do in order to contaminate biological evidence using that definition?
Well, in the area of the conventional type of typing we are talking about, you don't get results with--with samples that you can't see. It would have to be sufficient quantity that you are visibly seeing that you are transferring sample from one to the other.
And to your knowledge has there ever been a problem of contamination as I have defined it, inside of your laboratory in the serology section?
Okay. And in the area of PCR testing, do you use kits that are manufactured by an outside firm?
The company has changed names a couple times. It was originally Cetus. I believe it is Roche Biochemicals now.
And with respect to those kits, to your knowledge, has there ever been any defect in the kits that you were supplied?
Well, I was made aware of a time in our laboratory where we were getting results showing up in our controls and other areas in the process that was eventually, we believe, traced back to a particular lot of kits.
Well, we were showing a type within that system was typeable or becoming apparent in our controls in areas where we were not expecting to see any result at all.
Well, there are controls built into the system that allow you to check whether or not the presence of contamination. Contamination is a fact of life when it comes to forensic samples, so you always have control built in, both the controls that are picked up at the scene, plus controls that are introduced at different stages of the testing that should come out blank when you are all done, should not yield a result. And if a result is obtained during--you know in some of these controls, it shows that there is some sort of contamination occurring.
Now, was this an incident that you were personally involved in or had personal involvement with?
Did you ever read any documentation, around the time that it occurred, pertaining to the incident?
I was advised by the people that were doing the tests that upon receiving a new lot kit from the company we were no longer seeing that type showing up in our controls.
Well, when things are produced or manufactured they put a lot number on it so that you can track. I would assume they came from the same batch of chemicals or whatever in the factory, but it is an assigned lot number to a sequence of reagents or kits.
Okay. Now, going back to a conventional testing for a moment, in the area of conventional testing does the laboratory take proficiency tests?
Well, we subscribe to a couple of different outside companies that supply us with unknown samples. One of them is collaborative testing service and the other is cap or the College of American Pathologists. They send us case-like samples. We don't know the results of them. And as supervisor I would receive these items and either, if there was sufficient sample, divide them up between a number of the analysts within the laboratory, or if it was a small sample, assign to it one particular analyst, and they would test them, we would then submit our results to whatever company it happened to be, and then I get the results back from them at a later time.
And do you also take proficiency tests in the area of PCR testing in your laboratory?
The similar process. As a matter of fact, the--both CAP and CTS are gearing them more now toward the DNA process than conventional.
Now, we were talking a little bit about the substrate controls and the use of the controls yesterday. When you are doing your conventional testing, do you use those controls in any way?
I use them during the course of determining whether or not a sample is human and in the ABO testing.
When you use a substrate control, when you use substrate controls in this case, did you use the entire cloth square or a portion of it?
I would--I open up the bindle that contains it and I would make a cutting from it that is appropriate size for the tests that I want to run. I may not do a cutting. Sometimes I will actually take tweezers or forceps and tease out a couple of the threads or fibers that are present.
Because it is known that there are things out there besides ABO substances that will give activity or results that can mimic or look like ABO. Certain types of cloth can tend to give you what is called a false positive for an ABO antigen which is one of the things we look at when we are typing for the ABO system and you want to know if the surface with your stain on it is going to have this type of activity present.
And was it because of the ABO system for the reasons that you just described that you did?
What about for the other genetic markers that you are typing? Do you use the substrate control for that?
Well, as opposed to the ABO system where I mentioned there are things out there that can mimic the same type of activity, that is not true for the enzyme systems that we use.
What about the idea of testing them for the purposes of determining of whether there was any type of contaminant on the substrate control? Why won't you do that when you are testing?
Well, I do use it for the human test, and if that comes up negative, there is no biological material present that would give me a result.
Would you expect to get any result on electrophoresis, if you saw a substrate control that had no visible blood on it?
Now, in June and September of last year did you do certain testing on some of the items bearing the DR number of this case?
I this time I would like to mark what's called the "Serology results" chart as People's next in order.
Sir, directing your attention to People's for identification, have you seen this chart before?
Sir, showing you People's 202 for identification, does that summarize information that was contained on reports that you generated in connection with your testing in this case?
It summarizes information from the reports, plus some additional information from some of the notes.
All right. Now, starting first with the notes, what kind of notes do you generate when you are testing items contemporaneously with the testing?
Well, there is--while the testing is going on what is prepared is a serology case summary sheet which will eventually have a summary of all the results on each of the items. While I'm doing this I'm referring to some notes I have of my analysis from June of 1994, just so I can make sure I can remember all the different forms. So I described this as a serology case summary sheet. There is also what has been previously described "Serology item description notes." Those are the notes where we give a little bit more detailed description of the actual item. And then there are what are called electrophoresis work sheets that are created during the electrophoresis process. Each plate that you saw earlier will have a sheet that goes along with it to identify the different samples and where they are located on the gel. There may also be just note pages, blank pages. Sometimes we will write on the back of some these for some additional information.
Are the notations, the notes that you just referred to, ones that have been labeled with "L" numbers and provided to both sides in discovery?
Umm, now, which are the reports that are done at the time of the test? Which of the two types of reports that are done contemporaneously with the test?
Well, the type that is done contemporaneously with the test, the electrophoresis work sheet which would go along with each of the electrophoresis runs I described. There is also I mentioned that sometimes we will take notes on the back of a page. In the ABO blood typing test we don't have necessarily a form where that is recorded. A lot of times we just write the raw data on the back of one of the other pages and that is done while you are actually doing the analysis.
And what type of information or where did the information come from that was used to compile this chart? Was it just the reports, the analyzed evidence reports or also the electrophoresis work sheets?
I believe information that went onto this report came from my reports--or were put on this--came from my reports--a combination of that, the case summary sheet and the electrophoresis work sheets.
Now, does this particular chart contain test results of testing that you did between June the 27th and 29th on the reference samples, 17, 59 and 60 and also item 49?
Well, it depends on which part you are talking about. I did some and then I observed some placement and some of the actual hands-on work on the electrophoresis was done on Mr. Yamauchi.
When you say that the electrophoresis was done by Mr. Yamauchi, what did he do? Was it in your presence?
Well, one of the most important parts of that test, as far as sample continuity, is recorded on the electrophoresis sheet which sample goes in which lane and then making sure that the sample you are saying is on this sheet is actually in that lane. I sat alongside of him while we sampled, you know, opened up, in the case of, say, item no. 49, opened up the bindle, cut a small portion from the swatch, it was then placed into a numbered well which corresponded with a number on the electrophoresis sheet. And I watched him then transfer that into the gel along with the exemplar samples and the known standard samples that were included.
And then what happened after the gel had been run and the results were ready to be read?
At that point he took photographs of them. When I was available I co-read them with him and we determined what types were present on the plate.
Now, sir, do you recall testifying about the tests when you testified at the preliminary hearing in this case?
Counsel, directing your attention to page 4 of the preliminary hearing on July the 8th, 1994. I would like to read between lines 2 and lines 23.
Sir, at the preliminary hearing did you testify as follows to the following questions? "Question: I think where we left off yesterday I think you indicated that you tested item 49 which was the blood drop from the trail left at 875 South Bundy shown in the close-up of photograph e and shown in the perspective in photograph D. "Do you recall saying that? "Answer: That's correct. "Question: And you tested--and you tested that initially to determine if it was human origin? "Answer: Yes. "Question: And with respect to the blood samples that were retrieved from the Defendant and from Ronald Goldman and Nicole Brown Simpson, with respect to those samples, did you test them also? "Answer: Yes, I did. "Question: What test did you perform on those? "Answer: On those I performed the ABO blood typing test, the group 1 enzyme electrophoresis test and the PGM subtype electrophoresis test. "Question: And did you also subject the blood drop from the trail, item 49, to those same tests? "Answer: Yes, I did."
Now, sir, when you answered those questions did you specify that the physical loading onto the gel was actually done by Mr. Yamauchi in your presence?
And did you feel--were you trying to mislead anyone or leave Mr. Yamauchi out in answering those questions in that way?
Is it common in your laboratory for analysts to work together in the laboratory using a team approach such as that? Does that happen?
Now, Mr. Matheson, did you also generate an analyzed evidence report describing the testing that you did and Mr. Yamauchi did on these items?
And I would like to mark that as People's next in order. It is L-7778 for counsel's benefit.
It is entitled "Analyzed evidence report." The date the analysis completed is 6/28.
We are going to have to lower the serology results chart a little bit in order to put this on the elmo.
Sir, do you recognize the document that we just put on the elmo, People's 216 for identification?
And was this analyzed evidence report generated--when was this generated in relationship to the testimony at the preliminary hearing that we just read?
Well, it was generated immediately following testing prior to the preliminary hearing.
Okay. Can we see the full--first full paragraph where it starts with "ABO testing was performed."
And could you just read for us what you wrote in the first full paragraph saying--that starts "All ABO typing."
Well, the first paragraph is just that one line that says, and I am reading from a copy of the report myself rather than off one of the monitors: "All ABO typing was performed exclusively by Matheson, B-8927."
The next paragraph starts with: "Enzyme typing for ESD, PGM, PGM subtype and GLO were performed by criminalist Yamauchi, G-880. All evidence handling, including original sampling and transfers to the gel, were witnessed by Matheson. All results were confirmed in person or by photographs by Matheson."
So did you--why did you write these two paragraphs to describe what you did and what Mr. Yamauchi did?
Okay. And you wrote this paragraph out prior to testifying at the preliminary hearing where you said that you did the electrophoresis tests?
All right. Thank you. Now, we have been using the term "Reference samples." What does that mean?
The way I use it is it refers to the known blood sample or blood samples of a known source related to a case.
The reference samples that are designated on the chart are first indicated by the item number and then in parentheses by the person that they were taken from.
And when you do these tests are you comparing the results from the reference samples to the results that you get on the unknowns that are designated with these little blood drops?
Now, in September of 1994 did you also do another series of testing on items that are represented in the People's serology results chart?
And on September 11th what item numbers that are on the results chart did you test, if any?
Was when I started working on item no. 42, item no. 44, 50--item no. 54, item no. 84-A and B and item no. 85-A and b.
And on September the 20th did you do some testing on items that are contained on the serology results chart?
Okay. I'm going to be referring to my notes. I received some additional items on September 18th. As far as doing the analysis, yes, there was some analysis done on September 20.
When you say 13, on the chart we have 13-A. Is that the little cutting that you testified to earlier this morning?
And did you also do some testing on September the 27th on items that are contained on the serology results chart?
Again referring to electrophoresis work sheet, I did run some samples on that date, yes.
Now, with regard to these various items that are on the serology results chart, when you were looking at the Los Angeles Police Department evidence--evidence disposition summary boards, People's 177, did it contain the packaging of these various items represented on the photographs on those exhibits?
And when you were doing the testing was the--were the items coming out of the original packaging or the transmittal packaging that was used later on when it was sent out?
Okay. But in each case did you look at the item number and DR number prior to the test to confirm what you were testing?
Now, going back to the serology results chart, there is a column that says "ABO." What does that refer to?
ESD are the initials for one of the enzymes that we analyzed that I previously described.
Consistent with are a list of names that are placed there when a comparison could be made between the evidence samples and the exemplar or reference samples.
Frequency gives an indication of how common that combination of types occurs in general population.
Now, on this particular chart there is a number of items that are in blue that say "Inc." What does that mean?
Any result that is determined to be inconclusive at the time that it is run is written strictly as either inc or inconclusive on the report with no indication of the type given.
So it wouldn't say on your analyzed evidence report, for instance, for item no. 42, "Inconclusive b"?
It comes from a combination of the case summary notes and the original electrophoresis work sheet.
Well, why don't you write exactly word for word what is on the electrophoresis work sheet and the case summary notes onto the analyzed evidence report? Why don't they match a hundred percent?
Well, the electrophoresis work sheet is just that, it is a work sheet that is being used while the test is being run. You are recording the conditions of the test and you are recording all observations and in--not interpretations, but observations that are made on the plate. We even include guesses at that point. Our--and if it is a guess, it is marked as inconclusive. That information then is transferred over to the summary sheet intact, kind of summarizing the information on the work sheet. If it is inconclusive, it is marked as "Inc" and the potential or possible guess of the type is placed in that column. However, when a report is written, it just reflects "Inconclusive."
So is an inconclusive statement, if it says "Inconclusive B," does that mean that it could be wrong?
Well, inconclusive means just that, it is not a conclusive decision or conclusive result as to what the analysis showed.
KEY QUOTEAnd does that mean that as a forensic scientist when you say something is inconclusive, let's say on your work sheet, you said it was inconclusive B, would you be willing to report in Court that it was in fact a b?
Again, it is not a conclusive result. I don't want to put something down on my report or present to Court unless I'm sure as to what the result is.
So what is the point then of writing "Inconclusive B," for example, on the electrophoresis work sheet if you don't put it on the analyzed evidence report and you are not willing to testify in Court that it was in fact a b?
Well, because it is information. First off, the work sheet, like I described, it is things you are recording as you are reading it. I mentioned earlier that sometimes the band, they get darker with time and what may start out as a type with a question mark, or an inconclusive, over time may become a conclusive reading as it gets darker and more easy to read. There are times where you will record something as a potential inconclusive or with a question mark and that is the way it stays; it just never gets any better.
Well, potentially it can show--give you an idea what might not be there but it is still not a conclusive result.
Okay. Now, we were talking about degradation yesterday and whether or not a degraded sample could turn from one blood type into another. Do you recall that conversation?
And you said that that is not a problem except with respect to one of the genetic marker systems. What did you mean by that?
Well, the majority of the markers that we look at, like I mentioned, as they degrade they just get weaker and weaker and you can't determine a type. It doesn't change into another type. The most notable exception to that is in the system that goes by the initials of EAP. EAP is the type of system that I mentioned before that there were situations where it was the location of the band or the number of bands that tells you what type it is and there are other ones that deal with intensity of the bands. EAP is one of those types of systems. You look at the intensities and take that into consideration when you are determining what the type is. So in the case of EAP, it is known that a degradation route occurs where the bands become less and less intense and can eventually be mistyped.
Now, with respect to the PGM subtype, do you have those same issues in PGM subtype that you have in EAP?
Not when it comes to evidentiary samples. It has been shown that liquid blood stored for a long period of time, you can start slowly losing the minus bands. You will notice under the PGM subtype there is a plus and a minus indication. It is possible to eventually see the minus bloods degrade but that does not occur in dried samples.
So in dried samples such as a stain, what happens in the PGM subtype system when you get degradation?
The bands just become weaker and weaker to the point where when you develop it on the gel you just don't see anything.
Can you have a situation in the PGM subtype where the bands have degraded so that you can see something there but it is an inconclusive?
Oh, sure. That is another use of inconclusive, is that we know something is occurring where you can see that there is something there. Another indication we have goes by the initials of NA or no activity. If you see kind of a hazy appearance in the band area, you can't say no activity because something is going on, so it would be recorded as inconclusive.
So let's just take one example, item 13a that has the PGM subtype of 1 plus. Now, this was--is this a result that you classify as being inconclusive or is this a final result?
So what does that mean, as opposed to an inconclusive result in this particular case?
It means that the blood stain that was present on that item is a PGM subtype 1 plus.
Well, of the three parties that are on this chart, it is--can be--is consistent with the type that we found for item no. 59, Nicole Brown, and is inconsistent or definitely could not have come from the item no. 17 or in 60, Mr. Goldman.
Now, getting back to this issue that we were talking about on degradation, what about the ABO--what about the ESD results? Can degradation cause those results to change from one pattern to another?
So you have the four systems that we have here. Is EAP the only system that has this problem that you have been using where the degradation can make it appear to be something other than what it really was?
Now, Mr. Matheson, is this phenomena that exists within the EAP system, but not the others, one that is recognized in the forensic science literature?
And have you read articles that discuss the special issues that are inherent in the EAP system?
Did you read a chart, Mr. Matheson, that was by Dr. Grunbaum and Zajac entitled "Problems of reliability in the phenotyping of a erythrocyte acid phosphatase and bloodstains."
And did you consider that as part of this forensic science literature that we have been discussing that deals with the issue with EAP?
Grunbaum is G-R-U-N-B-A-U-M and Zajac is Z-A-J-A-C. The article is "Problems of Reliability of Phenotyping," P-H-E-N-O-T-Y-P-I-N-G, "Of Erythrocyte," E-R-Y-T-H-R-O-C-Y-T-E, "Acid Phosphatase," P-H-O-S-P-H-A-T-A-S-E.
By the way, it is erythrocyte acid phosphatase what we are designating with the initials EAP?
And in our preparations in our sessions where we discussed the case prior to your testimony, did you teach me at some length how to pronounce that term?
Sir, I'm showing you an article that we just read the title of. Is this one of the articles that you looked at?
And on page 617 of that article does Dr. Grunbaum discuss some of the issues that you have been explaining to us this morning about the EAP system?
"Although only a limited number of samples were used in this initial experiment, the results shown in table 1 clearly indicate that there can be a definite problem with the EAP phenotyping no matter which electrophoretic supporting medium is used."
Well, the electrophoretic supporting medium is in the case that we showed, the example agarose, there are just different types of terms that it can be run. The paragraph just indicates that there can be problems with this--using this system.
"Unlike other enzyme systems, EAP phenotyping depends not only on a pattern of relative distribution of bands but also on the relative intensities of the bands. When blood is aged, the individual isoenzymes" those are the bands in it, "Tend to degrade at different rates, further, exacerbating the difficulties of true phenotype identification."
I think you have explained this already in your testimony in different terms; is that correct?
Okay. And with respect to the last full paragraph under "Summary," can you read that for us?
"Erythrocyte acid phosphatase is a useful system for the crime laboratory for both fresh and degraded blood and bloodstains, provided the inherent problems of phenotyping this particular enzyme system are recognized. Because of the great number of variables affecting this enzyme system in vitro, phenotyping should not be attempted until the complete history of origin and handling of the sample is known."
Now, with respect to the last point about not typing erythrocyte acid phosphatase unless the complete history and origin of the sample is known, what does that refer to?
Well, his reference there I believe is suggesting that you should not be doing this until you know exactly what the history of it is, which means where it was deposited, potentially the length of time, the conditions it was under, as opposed somebody just walking into a laboratory with a blood stain.
Your Honor, I object and move to strike. No foundation that he knows what that author meant.
Sir, within the forensic science community is there a--are there analysts that believe that you should know the complete history and origin of a sample before starting EAP testing--before making an EAP conclusion?
What did you understand that to mean in terms of your reading of the article and your interpretation of the article?
Well, my reading of that, I understand as being suggested that it is important to understand the history behind a sample, what conditions it was collected and preserved under.
And where do you stand on that particular issue as to whether or not that is necessary?
Well, I kind of sit in the middle of it. There are differences of opinion of this and this has been an area of discussion when it comes to dealing with samples and serology in general, in that some people feel it is very important that the criminalist not be biased by any sort of outside information or receive a blood stain, you know, cold without anything and you just report the results that you find. There are also those that believe, as indicated in that article, that it is important to know the background, the story behind how the sample was deposited and taking all of that into account. I don't really believe in either extreme. I don't particularly like to work in the dark. That is very difficult to do. However, I also appreciate the fact that you do not want your opinion biased in anyway by any information that isn't directly related to the evidence.
Okay. Now, with respect to the EAP system you were talking about that in this system, that not only do you look at the bands but you also look at the intensity of the band; is that correct?
Well, in PGM subtyping it is the location of the band, where it appears on the gel in relation to your known standard, as opposed to how strong or how light the bands are.
So you are not looking at the intensity or brightness the band when you are talking about PGM subtype?
Given that you are looking at the intensity of the band on EAP as opposed to PGM subtype, is there some element of subjectivity in terms of making a call as to an EAP result?
Well, not only do these systems differ in intensity versus band location, they are also developed differently. The PGM system is developed, you get a dark blue, almost black band that you look at under visible light. In the EAP system the band you are looking at, you have to look under ultraviolet light, and rather than being dark they are actually a light source, they are bright. And people's eyes see different things, as far as the intensity of what they are looking at. It is a very subjective call.
Mr. Fairtlough, can you lower it down a little bit so perhaps we can also put some pictures on the elmo later on.
Mr. Matheson, showing you People's 217 for identification, what is this exhibit?
What this exhibit shows is a block diagram or kind of a graphical representation of the six most common EAP phenotypes.
Now, maybe we could just take a look at the photograph on the evidence testing board again that shows the plates on the electrophoresis machine. While we are waiting to put that up, can you go through the six common phenotypes and just explain to us--well, first of all, I know you have already described this, but a phenotype is what again?
Well, it is the type that is observed on the gel. It is identified for the eventual reporting.
They appear on the right-hand column there; type A, type B, type C, type BA, type CB and type ca.
And when you are testing a system using the EAP system, is it--does it fall under one of these six types generally?
Now, if you can take a look at our evidence testing board, we have a photograph of items being loaded onto the gel. Can you just orient these two exhibits for us and tell us I mean how this would correlate?
Well, to put the two in relation to each other, if you were to take the electrophoresis plate that you see up there and rotate it ninety degrees to the left, we are just putting the sample in what we refer to as the origin--the origin, the place where the sample starts, and that would correspond in the EAP diagram to the line or the area that is marked with the word "Origin" right above it.
And then you were talking about how after the electrophoresis machine is hooked up, the sample begins to migrate across the gel and that it creates a banding pattern. Can you describe for us what that would look like using the EAP phenotype board?
Well, using this as an example, you would start at the origin--we have already mentioned lanes, and a lane would refer to an area where a sample is placed and then it moves. It moves along in roughly the same size and shape or configuration as where you originally put your sample. So in this particular example we have six lanes that are marked by the six different types. Your sample would be placed in the origin well, at the origin, a current would pass through it and the different portions of the enzyme would be moving along. And at some point you stop that and develop it and you see the bands and their location.
Now, you said that when you are looking at this plate you look not only at the placement of the band, but also intensity. Can you describe that for us using this diagram?
Well, the--it is a block diagram and it is not an actual photograph or something of a plate. It is just a graphical representation of it. We look at intensities in the system. We also look at locations, where the bands appear. It is a combination of the two. As you can see under the lane that is marked "A," the block diagram shows bands in different places than in the B. I also want to point out at this point that we show a block appearing on the far left of it in each of the lanes. This is just consistent with every type and is insignificant when it comes to determining what the type is of the sample. So you see that the location difference between the a and the B, however, also graphically demonstrated by this, is the fact that they are of different sizes and the sizes are an indication of the intensity. You will notice in the a that they are about equal size, they show about equal intensity or brightness. The B, the larger block band, would show up as significantly brighter than the smaller block band in the B column, and that is consistent throughout the rest of the items.
Your Honor, I'm sorry, I was so excited about this EAP block diagram I didn't see that we had run over.
All evidence handling, including original sampling and transfers to the gel, were witnessed by Matheson. All results were confirmed in person or by photographs by Matheson.
Inconclusive means just that, it is not a conclusive decision or conclusive result as to what the analysis showed.
Not in my experience and knowledge, no.
I didn't think it was necessary.