Articles Posted in Experts

This is the name given to statistical errors that can arise when deciding the probability that a DNA sample is that of the accused.  This is potentially more meaningful than usual to Troy Brown who was convicted of sexual assault and attempted murder.  He has a twin brother.

This transposition of the conditional probability can produce results that range from the approximately correct to the grossly inaccurate. Without discussing the extent of the mathematical error, Mueller’s letter stated that this transposition was "so common it has been given a special name, the prosecutor’s fallacy."

Indeed, the fallacy abounds in the statements of judges, defense counsel, and journalists. Statistics textbooks, evidence casebooks and treatises, and judicial opinions all caution against it.

I’ve already noted that Briscoe is a very interesting follow-on to Melendez-Diaz about the use of forensic analysis reports at trial where the chemist is not called as a witness.  See here, here, and here.

Here is a link to the Brief just filed on behalf of the

07-11191 Briscoe v. Commonwealth of Virginia

ACCA has issued a Memorandum Opinion in United States v. Markis, ARMY 20070580 (A. Ct. Crim. App. 18 August 2009).

Appellant had given three pre-trial admissions to CID.  The defense sought to exclude the confessions as being coerced.  The military judge permitted the defense to present expert testimony on coerced confessions, specifically it appears how the Reid Technique may lead to coerced confessions.  However, the military judge refused to allow the defense to ask hypothetical questions unless the defense first asked for an Article 39(a), UCMJ, session to get a ruling.  It appears that the defense did not seek to ask a hypothetical and did not ask for an Article 39(a) once the prosecution witnesses had testified and they had laid a sufficient foundation to get to the point where a hypothetical might be offered.

The opinion has a nice little review of what you must do, by way of proffer, to preserve an objection.

We have jurisdiction under 28 U.S.C. § 1291. Concluding that the district court did not abuse its discretion in allowing the government to present expert evidence that a thumb print found on some of the contraband recovered by the authorities was a match to Baines’ print, we affirm the judgment of the district court.

United States v. Baines, No. 08-2098, 2009 U.S. App. LEXIS 15945, at *1–2 (10th Cir. Jul. 20, 2009).

I’ve commented earlier that I do not see Melendez-Diaz altering the drug urinalysis case in terms of laboratory evidence.  Here is some additional thought which I think supports my conclusion.

Q2: Peer review, forensic experts.

One question that came up during oral argument, and remains after the ruling, is the application of the ruling to peer review witnesses. It is common for a supervisor or peer to review a forensic examination, as part of a quality control process. The reviewer often does not conduct the specific analysis or testing.

Here is the lead in for an piece on federalevidence.com blog:

In medical malpractice case, trial court’s exclusion of defense expert as unqualified was not harmless error; the defense expert’s opinion that the plaintiff’s expert’s conclusion was not supported by the medical literature plaintiff cited did not require the defense expert to have as much specialized “training and experience” as the opposing expert whom he critiqued, in Huss v. Gayden, __ F.3d __ (5th Cir. June 10, 2009) (No. 04-60962)

The lack of precision in the Daubert test for the admission of expert witness testimony serves as a source of its remarkable flexibility and also as a source of frustration to practitioners. It is clear that under Daubert, an expert witness need not be a star in his or her field to qualify. On the other hand, minimal preparation or training frequently is insufficient for expert qualification. The Fifth Circuit recently probed the question of just when an expert is “expert enough” in a medical malpractice case. The result reached by the circuit demonstrates that expertise is a matter that must be assessed within the context of the evidence presented and arguments that will be made at trial.