Your Honor, we would renew our objection based on People versus Collins, that the multiplication of these factors is improper unless they can lay a foundation to show the independent appearance of each of these factors that they're multiplying.
Yes, your honor. Counsel is raising the possibility of linkage, and I think we may be -- with maybe a little bit further questioning, I can establish that that is not an issue in these particular markers. That's more an issue in other areas. If I may?
Are you familiar with any studies that discuss the possibility of linkage in the systems that you have tested for the purposes of your testimony today?
In this particular case, dealing with these factors that have been around for -- and used for many, many years, I right here cannot specifically come up with any studies. It is just something that has existed for quite a while.
In the scientific community has there been any agreement concerning the existence or non-existence of linkage with respect to the ABO, ESD and PGM sub-type categories?
My understanding is there's general agreement that there is no linkage between any of these factors.
KEY QUOTESo that as of this date the scientific community agrees that there is not the problem of linkage that might otherwise skew the frequencies that are reported in all these cases where these particular markers are tested and found in blood types and in blood stains for the purpose of determining frequency?
That's correct. These sort of determinations have been made and used in court for in excess of a decade.
Now, you indicated, sir, that you do not -- the table that you like to use does not consider -- does not break down by race.
Is that a more conservative approach than focusing first on the race of the suspect and then extrapolating out from that to see what tables would be fit based on --
Why don't you consider -- why don't you like to consider race when you determine the frequencies and choose your tables?
There is actually a couple of reasons. I believe I mentioned one earlier. In that as a criminalist, as a scientist, I receive a piece of evidence that is, say, in this particular case, a bloodstain left on -- at a crime scene, I have no knowledge of who potentially might have left that behind. I don't want to assume that it is a caucasian or it is a black or hispanic or something along that line; So I prefer to use our general frequency considerations that we do because it gives kind of a middle number, where all the different races are considered within the population of the city of Los Angeles. Like I mentioned earlier, I do have statistics broken down as to how it might be given a caucasian, black, hispanic; but I don't prefer to use those just for the reasons that I mentioned. Also, I feel it is important for us to have our own data that we can support, where we know where the information came from; and it is not always possible for us to receive information as to the race of an individual whose blood we are typing. And even if we did have a process of receiving it, there is some question as to the validity of how that is determined. Does the person drawing the blood just look at them and make their own determination, or what? So we Prefer to go with the general characteristics.
If, for example, you were to consider "well, the suspect is white; therefore, I am going to look at the types for white people" concerning the frequency of each marker that you are testing, does that basically begin by narrowing the focus, by making the assumption that your evidence stain will be from a white person?
And in that regard, sir, might that distort the frequency to make it unfairly more incriminating than you otherwise might have if you did not make any assumptions about the possible source of a bloodstain?
Well, depending on how it happens to work out for that race, it could be either more or less incriminating.
But either way, it might distort your result if you were to narrow the focus by making the assumption the person who left the stain is the same race as the suspect?
Now, I take it, sir, then, that you found, as you reported, that the types detected in the blood drop of item 49, left on the trail at 875 south Bundy, occurs in 43 percent of the population?
And who among the three that you have listed in the chart marked People's 24 could possibly have been the source of that stain?
Of the three people that are described both in my report and on the chart, only Mr. Simpson can be included in that percentage of the population that could have left that stain.
KEY QUOTESo Mr. Simpson alone is included in the 43 percent of the population that could have left the blood drop on the trail at 875 south Bundy?
Then by my math, if my math is any good, we may fairly say that 99.57 percent of the population is excluded as a possible source of the blood drop found on the trail at 875 south Bundy, marked as item No. 49?
Of the three people that are described both in my report and on the chart, only Mr. Simpson can be included in that percentage of the population that could have left that stain.
99.57 percent of the population is excluded as a possible source of the blood drop found on the trail at 875 south Bundy, marked as item No. 49?
My understanding is there's general agreement that there is no linkage between any of these factors.
I receive a piece of evidence that is, say, in this particular case, a bloodstain left on -- at a crime scene, I have no knowledge of who potentially might have left that behind. I don't want to assume that it is a caucasian or it is a black or hispanic or something along that line.