You do solemnly swear that the testimony you are about to give in the cause now pending before this court shall be the truth, the whole truth and nothing but the truth, so help you god?
I do. Greg Matheson, called as a witness by and on behalf of the People, was examined and testified as follows:
I am a supervising criminalist employed by the city of Los Angeles, working for the Los Angeles police department crime lab.
I have a bachelor of science degree in criminalistics from California state university at long beach.
Criminalistics, that is a science that is involved with the collection, preservation and analysis of physical evidence. We employ a lot of different natural sciences towards that end.
And as a student, sir, did you begin to learn the field of criminalistics by working in some fashion?
Well, initially, prior to working for the Los Angeles police department as a criminalist, I was a student worker and community service officer for the Culver city police department. In that capacity I learned how a department operates. I had a chance to learn something about field investigations, fingerprinting, crime scene photography.
Now, did you indicate how long you have been a criminalist with the Los Angeles police department?
And of those 16 years, how much of them were spent doing latent prints or serology or other -- a Well, as a criminalist I never have done any sort of latent print work. I started initially -- about my first 18 months, I was assigned to the toxicology unit, to the crime lab. I was then moved to an area called special testing. I was in that for a little over 18 months. Then I was assigned to the serology unit. I have been in the serology unit in one capacity or another for the last 13 years.
The serology portion, or unit, of the criminalistics laboratory is involved in the identification and analysis of body fluids. Our interest is, first, identifying whether or not a particular fluid or stain is a fluid of interest and then, once that is identified, to be able to determine the genetic markers, or the makeup, of that stain or fluid in an attempt to compare it back to a possible source of origin.
Now, is your current position one of a supervisory nature, or is it one of the rank and file, if you will?
Yes. The first four years as supervisor was strictly of the serology unit; but starting last -- I believe it was last July or August, I also was placed over direct supervisory control of our trace comparative unit, our field unit, the forensic photographer and our chemical processing unit.
We have a couple of criminalists assigned to what we call the field unit. These are criminalists that are responsible for handling responses to daytime field calls. They are also at that time either working in another unit or also training in another discipline.
Specifically, as far as an academic course, I attended a two-week class that was offered by the f.b.i. in their academy in quantico, Virginia; and it was entitled "biochemical analysis of bloodstains." It was offered at the academy but through the university of Virginia.
And was there any training that you received while on the job when you began with LAPD from other criminalists?
Yes; Throughout my career. You receive on-the-job training from other criminalists upon entering a new unit. Even though you have the basic scientific background, understand the concepts and things that are being presented, you always have to learn from the criminalists who have been in the unit for a while the exact procedures and techniques used by that particular unit. So yes. The first several years was involved in picking up these techniques from the criminalists that had been performing them for quite a while.
Now, have you received any kind of certifications or become a member of any professional organizations?
Yes. I am a member of two professional organizations and hold two voluntary professional certificates.
One of them was initially offered by the California association of criminalists, and it was a certificate of professional competency in criminalistics, or a general background certificate on the whole field of criminalistics. Approximately -- I believe it was about a year and a half ago or so, the program was turned over to the American board of criminalistics, which rather than being a state-based body is a national body, organization, whose sole purpose is the certification of criminalists throughout the country.
I received what is called diplomate status in that organization -- or a general knowledge in criminalistics.
Yes, it is. It is what is called a regional association of forensic scientists that, even though it is based in California and the majority of members are in California, has quite a few in other states and a few other countries.
The standards to become certified -- yes. You need to be in the field for two years plus pass a written examination.
In January of 1987, I was placed by the association as the chair of what was called the certification committee; and it was that committee that established the program that eventually became the CAC's certification program. As committee chair I was involved in establishing the minimum standards, figuring out the processes that would be used in handling the whole certification sequence along with working with the criminalists, also, that were assigned in making up the general test.
Have you held any executive-type positions in any of the other organizations such as the American board of criminalists?
Yes. The American board of criminalistics, when it was formed, because of my association with the California association of criminalists, I was asked to be part of the original formation of the ABC, or the American board of criminalistics; and I held the position of vice-president of that organization.
Are you familiar with an organization named the California association of crime lab directors?
And with respect to the California association of criminalists, have you held any executive positions in that organization?
Well, up until may of 1994, the previous four years I held board of director positions. The first year I was called a regional director south, or the regional director for the southern part of the state. Then I was elected to president-elect position, served one year as that, one year as president and last year was board position of immediate past president. As of may I was off the board of directors.
Mainly it is within the department. I teach serology and basic field techniques at the homicide detectives school, the sexual assault detectives school and, more recently, the detective supervisors school. I was also able to be involved in, I believe it was, in 1987, four training sessions that were offered throughout the state by the office of criminal justice planning on the new protocol that was established for collecting sexual assault evidence.
Well, I have direct supervisory control of, I believe it is, 19 employees at this Time and, in that role, have basic administrative control or responsibility over the units that I mentioned earlier, assign days off, handle sick reports, all sorts of administrative things that go along with that. In addition to those duties, I am still involved in some of the day-to-day operations of the technical aspects of the serology unit, which is more my specialty than the other ones. A regular duty of that position is I read all the reports that are created by the criminalists within that unit, do both a technical review of the report and check for just misspellings, WORDING and that sort of thing. Towards that end, I examine the report, pull all the notes associated with the report, make sure that the data that is presented in the report fits the raw data that was obtained during the course of the analysis and then make sure that the data that is included in the report is consistent with the conclusions, that the conclusions could be supported by that data.
You are still involved in the technical aspects of things, the actual work done in the serology unit?
That's correct. Not to the extent I used to be; but towards that end, I am also involved with confirming -- occasionally confirming electrophoresis results, which is one of the techniques used in the laboratory.
That is one of your functions as a supervisor -- to occasionally be called on to confirm results?
And in that regard, sir, in serology, is it one of the functions to detect genetic markers such as abo and proteins and enzymes?
Well, within -- probably, for simplicity, we will talk about bloodstains. There are other body fluids the unit deals with, but in somebody's blood there are what are called genetic markers. These are factors that exist in the blood that are acquired genetically from your parents and exist in certain discreet types. Probably the best example that can be given of that is the abo blood-type system. That is one of the genetic markers we look at. You are either type a, b or type o; And that is determined by the types your parents have. In addition to the abo system, there are also other genetic markers that are enzymes, proteins that are found in the blood system; And they also exist in discreet types just like I described in the abo system, an example being one that goes by the name of Esterase D, esd. You are either type 1 or type 2. These types are identifiable in a bloodstain. Once a stain is categorized, then we analyze a liquid sample from a known source to see if there are similarities between -- if they have the same types. If they do, they could be from the same source. If there are differences, then that source is eliminated as a source of the bloodstain.
Is that very typically what you do in that serology unit? Forensically speaking, you determine whether an item of evidence, say a bloodstain found at a crime scene, could come from a particular person, comparing the types found in the bloodstain to the type of blood withdrawn from the person?
That is the main thrust of the unit -- to perform these analyses but not only to try to include somebody but exclude somebody. If the types differ, then they are excluded as being a source of that sample.
Electrophoresis is a technique that is utilized to determine the types of the enzymes or proteins that I mentioned earlier. It is not used in the abo system but in these enzymes. It is, simply put, a protein or enzyme, depending on the structure of it, will have a slightly different charge to it; so the technique involves pouring a plate that is maybe 8 inches square, something like that, with agarose, which is kind of a jello-like material. The samples then are placed on threads and established in a certain location on the gel. Current is allowed to run through it, and the enzymes or the proteins located in that sample are spread out throughout this gel. When that is done, certain identification chemicals, visualization chemicals, are placed on top of it that react with the individual enzymes and allow us to see where they travel to. In essence, we get a band that occurs in the gel at a certain spot. We always run controls on those of a known type, which tell us where a band is supposed to show up for a particular type. If an unknown sample matches the location of those bands of a known sample, we then can assign that type to the unknown sample.
Well, it is not done consecutively. It is done at the same time. A typical gel will have, say, 12 different samples on it; and out of those 12, you may have four known, or standard, samples on it. And the remaining eight or nine spots are taken up with unknown samples. They are all run together so you can do a direct comparison of the location of the bands to each other.
Now, with the enzyme and protein testing in addition to the abo testing, are you able to give smaller numbers in terms of the number of people that could possibly have been the origin of a bloodstain, for example?
That's correct. Part of the comparison involves trying to add some significance to the information that we receive, An example being, going back to the abo blood system, if we determine that a stain is abo type o, that exists in about 48 -- say 50 percent, or half, of the population. If we just had that one test, all that would do is eliminate half the population and include the other half as a possible source of that blood. At that point we would run some of these enzymes; and with each additional marker or with each type that we determine, the potential population of people that could have left that stain gets smaller and smaller. If we have a bloodstain that is a type o, which is 50 percent of the population, and identify another factor that is also 50 percent of the population, the combination of those two means that now you are down to 25 percent, or you have cut the number in half. With each additional test, that number, or possibility, gets smaller and smaller.
Now, in this particular case, sir, did you supervise and assist in the testing of some bloodstains and blood samples?
I supervised and assisted in part of it, and I directly ran the tests in part of it.
KEY QUOTEIn your experience, sir, does all evidence received by the lab for analysis bear a D.R. number?
And does each case have its own discreet d.r. number in order to keep all the evidence organized in one place?
June 24 was the date the request was made. I was not around when that request was made. I actually didn't find out about it until the next day and then didn't start the testing until the 27th.
Now, item No. 17, is that described as the whole blood of the defendant, Mr. Orenthal Simpson?
And No. 49, is that described as the blood recovered from the crime scene as photo i.d. no. 114?
And showing you, sir, People's 19, photograph "e," do you see the number 114 in that photograph?
And does that correspond, then, to the photo number of the item No. 49 that you tested in this case?
With respect to that item, I ran a presumptive test for the presence of blood to determine whether or not the stain was in fact blood. Then I ran a test to determine whether or not it was human in origin. The additional test run at that point was the abo test that I previously described and then two enzyme tests, one of them that goes by the designation "group 1," which includes three enzymes, and then an additional test that goes by the designation of "pgm subtype."
KEY QUOTEIf the types differ, then they are excluded as being a source of that sample.
I supervised and assisted in part of it, and I directly ran the tests in part of it.
With respect to that item, I ran a presumptive test for the presence of blood to determine whether or not the stain was in fact blood. Then I ran a test to determine whether or not it was human in origin.
With each additional test, that number, or possibility, gets smaller and smaller.