Saturday, November 4, 2017

Louisiana's Court of Appeals Brushes Aside PCAST Report for Fingerprints and Toolmark Evidence

A defense effort to exclude fingerprint and toolmark identification evidence failed in State v. Allen, No. 2017-0306, 2017 WL 4974768 (La. Ct. App., 1 Cir., Nov. 1, 2017). The court described the evidence in the following paragraphs:
The police obtained an arrest warrant for the defendant and a search warrant for his apartment. During the ... search ... , the police recovered a .40 caliber handgun and ammunition ... The defendant denied owning a firearm ... .
     BRPD [Baton Rouge Police Department] Corporal Darcy Taylor processed the firearm ... , lifting a fingerprint from the magazine of the gun and swabbing various areas of the gun and magazine. Amber Madere, an expert in latent print comparisons from the Louisiana State Police Crime Lab (LSPCL), examined the fingerprint evidence and found three prints sufficient to make identifications. The latent palm print from the magazine of the gun was identified as the defendant's left palm print.
     Patrick Lane, a LSPCL expert in firearms identification, examined the firearm and ammunition in this case. Lane noted that the firearm in evidence, was the same caliber as the cartridge cases. ... He further test-fired the weapon and fired reference ammunition from the weapon for comparison to the ammunition in evidence. Lane determined that based on the quality and the quantity of markings that were present on the evidence cartridge case and the multiple test fires, the weapon in evidence fired the cartridge case in evidence.
Defendant moved for "a Daubert hearing ... based on a report, released by the President's Council of Advisors on Science and Technology (PCAST) three days before the motion was filed, which called into question the validity of feature-comparison models of testing forensic evidence." The court of appeals decided that there had been such a hearing. The opinion is not explicit about the timing of the hearing. It suggests that it consisted of questions to the testifying criminalists immediately before they testified. In the court's words,
[B]efore the trial court's determination as to their qualification as experts and the admission of their expert testimony, Madere and Lane were thoroughly questioned as to their qualifications, and as to the reliability of the methodology they used, including the rates of false positives and error. The defendant was specifically allowed to reference the PCAST report during questioning. Thus, the trial court allowed a Daubert inquiry to take place in this case. The importance of the Daubert hearing is to allow the trial judge to verify that scientific testimony is relevant and reliable before the jury hears said testimony. Thus, the timing of the hearing is of no moment, as long as it is before the testimony is presented.
The court was correct to suggest that a "hearing" can satisfy Daubert even if it was not conducted before the trial. However, considering that the "hearing" involved only two prosecution witnesses, whether it should be considered "thorough" is not so clear.

As for the proof of scientific validity, the court pointed to a legal history of admissibility mostly predating the 2009 NRC report on Strengthening Forensic Science in the United States and the later PCAST report. It failed to consider a number of federal district court opinions questioning the type of expert testimony apparently used in the case (it is certain that "the weapon ... fired the cartridge case"). Yet, it insisted that "[c]onsidering the firmly established reliability of fingerprint evidence and firearm examination analyses, the expert witness's comparison of the defendant's fingerprints, not with latent prints, but with known fingerprints, ... we find [no] error in the admission of the testimony in question." The assertion that the latent print examiner did not compare "the defendant's fingerprints [to] latent fingerprints" is puzzling. The fingerprint expert testified that "[t]he latent palm print from the magazine of the gun was identified as the defendant's left palm print."That was the challenged testimony, not some unexplained  comparison of known prints to known prints.

The text of opinion did not address the reasoning in the PCAST report. A footnote summarily -- and unconvincingly -- disposed of the PCAST report in a few sentences:
[T]he PCAST report did not wholly undermine the science of firearm analysis or fingerprint identification, nor did it actually establish unacceptable error rates for either field of expertise. In fact, the PCAST report specifically states that fingerprint analysis remains “foundationally valid” and that “whether firearms should be deemed admissible based on current evidence is a decision that belongs to the courts.”
"Did not wholly undermine the science" is faint praise indeed. The council's views about the "foundational validity" (and hence the admissibility under Daubert) of firearms identification via toolmarks was clear: "Because there has been only a single appropriately designed study, the current evidence falls short of the scientific criteria for foundational validity." (P. 111).

As regards fingerprints, the court's description of the report is correct but incomplete. The finding of "foundational validity" was grudging: "The studies collectively demonstrate that many examiners can, under some circumstances, produce correct answers at some level of accuracy." (P. 95). The council translated its misgivings about latent fingerprint identification into the following recommendation:
Overall, it would be appropriate to inform jurors that (1) only two properly designed studies of the accuracy of latent fingerprint analysis have been conducted and (2) these studies found false positive rates that could be as high as 1 in 306 in one study and 1 in 18 in the other study. This would appropriately inform jurors that errors occur at detectable frequencies, allowing them to weigh the probative value of the evidence. (P. 96).
To say that the Louisiana court did not undertake a careful analysis of the PCAST report would be an understatement. Of course, courts need not accept the report's detailed criteria for establishing "validity." Neither must they defer to its particular views on how to convey the probative value of scientific evidence. But if they fail to engage with the reasoning in the report, their opinions will be superficial and unpersuasive.

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