Thank you. No further questions.

RECROSS-EXAMINATION BY MR. BLASIER:

Mr. Sims, the reference vial wasn't sent to Dr. Cotton, was it?

Objection. No foundation.

BY MR. BLASIER: Do you know?

I -- I know that they did not.

I know what they did receive. They did receive some swatches of reference samples. That's what I do know.

All right. And the swatch -- and the surface that is used, if it's a different surface, you can get a different quality of DNA, correct?

If it's -- you mean a card versus a piece of cloth, for example?

Or card, piece of cloth versus a vial.

Well, again, your example, we talked earlier where it sat in the vial for longer.

That could cause a difference, yes.

To degrade. So if you took blood out of the vial on day one, it might be higher quality than if you took it out on day thirty?

Yes.

Okay.

And the cloth swatches that you got from the coroner's office, do you have any idea whether they were made from the reference vial or they were done at the autopsy from blood directly from the victims?

I don't know that personally.

Now, Mr. Lambert asked you about the fact that some of these alleles are very close together in terms of their base pair sequence. Do you remember that?

Yes.

And that's what can cause cross-hybridization, a DX gene; those are alleles that you -- one allele you can excuse for a another one because they are close together?

The DX is another phenomenon. But, for example, in the cross-hybridization, there's not that much difference, say, between some of the probes and sequences on the alleles.

That's why you can have confusion between a 1.1 and a 1.3. You can have a 1.3 show up that's not really there in the sample, but it's cross-hybridization from the 1.1 or the 1?

Again, you're talking about degrees of showing up.

When you put it that way, for example, all we still see, the true type, but you may see some of the background reaction.

And in this case, where we have the 1.1 alleles involved and the 1.3 alleles involved, that becomes more of a consideration because those are the ones that can get confused, correct?

Well, yes, to answer your question.

Thank you.

And the reference sample might chart the typing on the reference sample. Those results are from your documentation, are they not, the hints and the traces?

Yes.

You saw them there, didn't you?

When I looked at them in the laboratory, I saw some very faint background dots, yes.

And only DNA will cause that to light up unless the strips's bad, right?

Yes; only DNA will cause that.

Now, let's talk about -- Mr. Lambert asked you questions about the formula, the product rule --

Yes.

-- in one of the national commissions, he asked you about the National Research Council.

Tell me what that body is.

The National Research Council is a group of scientists -- I don't know all the administrative details -- but what they do is, they form committees to study questions in the -- scientific questions in the public interest; for example, a recent study they did had related to the effects of living near high voltage lines, that sort of thing.

They may do a study on something like is fluoride is good to have in the toothpaste for dental reasons.

In this case, they addressed the issue of the use of DNA in the forensic context.

And the committee is made up of highly regarded highly respected scientists, correct?

Yes, they are scientists. Sometimes they're lawyers and judges, also.

But they're represented by population geneticists, molecular biologists, statisticians, and people that are knowledgeable about these kinds of statistical ideas, correct?

Yes.

And the National Research Council did a lengthy study and they issued a report called the NRC report, did they not?

Yes; that was in 1992 was the first report.

And they concluded that you shouldn't use the product rule because of population substructure potential problems because -- did they suggest a different formula?

Well, they still incorporate in the product rule, but they used a different formula for the allele individual band frequencies.

That's called the ceiling principle, right?

Yes, it is.

And if you use the ceiling principle that they recommended, you come up with much more -- much different numbers, don't you?

You can get vast differences in the magnitude of the numbers by applying the ceiling principle, rather than the product rule, can't you, Mr. Sims, depending on the particular alleles; but that can happen, can't it?

It could vary like across several of these, that when you look at this many loci, you can see it shift a few decimal places, yes.

That created tremendous controversy in the scientific community about using the product rule, didn't it?

No, it created a controversy about whether or not that approach to the allele frequency is correct. Nobody ever challenged the use of the product rule in those NRC reports.

There has been litigation in the last five years, at least, that you've been involved in -- that you've been involved in on this very point, as to whether you can use the product rule because of population substructure problems.

Objection. Irrelevant.

Overruled.

Objection. Argumentative; irrelevant.

I'll sustain that.

BY MR. BLASIER: The NRC appointed a committee of a second set of scientists to do another report, and they came up with a different conclusion, didn't they, about which formula to use?

They abandoned the idea of the ceiling principle; they felt that was not a good approach.

They suggested some other factor, adjust for population substructure that hadn't been suggested in the first report, correct?

Well, they --

Isn't that correct?

They did on some of the PCR markers, for example, when we're looking at very limited discrete allele systems, but they basically concurred with this approach that we've used in the RFLP analysis.

There are studies going on to determine whether population substructure is a statistically significant problem when you use the product rule, correct?

Well, now, you've got a lot in that question. Because you talk about statistical significance and whether or not there's practically any significance -- I don't think there's any argument now that practically it's not significant.

Mr. Sims, my question was --

He was in the middle of his answer.

I move to strike it as nonresponsive.

I think it's responsive.

I'm sorry?

He is responsive.

Go ahead.

You may finish.

We talk about statistical significance versus the practical significance. And the NRC second report has basically said that this approach that we used in this case is a valid approach.

And the concept you're talking about is, there were studies done to determine whether there were significant differences among subgroups of people that might affect the use of the product rule, correct?

Well there's been -- more data has been gathered and analyzed, yes.

There's been a lot of work done in that area, hasn't there?

Yes.

Those studies have shown that, yes, there is a statistically significant difference among subgroups of people that affect your ability to use the product rule, correct?

Statistically significant?

There may be some statistical significance there, yes.

But now we get very -- it gets very complicated here, because we're talking about differences, for example, among say, African persons versus Caucasians, and then there's differences there, too, with regards to -- say you know you're European group rest is another European, something like that.

The critical point, though, in all this is that the variations that's really out there is among individuals.

It's where the variation is, in other words, sure there are some differences, for example, between whites and blacks, but the real variations among us as individuals is vast amounts.

There are studies that showed statistically significant differences. When they came out, you folks in the forensic community came up with a concept of well, we'll say they aren't forensically significant, didn't you?

Well, I didn't invent that term.

That was invented by somebody.

Thank you. Nothing further.