Commonwealth v. Patterson, 445 Mass. 626 (2005)

Developing technology has provided law enforcement with innovative ways to “fight crime” and “catch the bad guys”. From DNA profiling to blood spattering analysis, investigators can indict an unknown individual based on the genetic “id” left behind at the scene of a crime and even determine the position of an individual when their lives were extinguished. However, one area of forensic science that still relies heavily on the “naked eye” is fingerprint analysis. Fingerprints are analyzed objectively and subjectively, depending on what level of testing the expert is executing, and “positive ids” often result in law enforcement catching to right “bad guy”.

However, the Massachusetts court in the present case, drew the line between complete latent prints and simultaneous latent impressions that fail to “prove” the identity of an individual when viewed one at a time. In Patterson, the court felt it necessary to protect individuals who might be implicated by incomplete prints alone, because the court did not believe identification by “simultaneous prints” had been proven sufficiently reliable.

The Big Picture

In February 1995, Terry Patterson was convicted of armed robbery, possession of a dangerous weapon, and the September 1993 murder of Detective John Milligan. Commonwealth v. Patterson, 445 Mass. 626, 2005 WL 3503603 (Mass. 2005). His convictions were set aside in 2000 based on the finding of ineffective assistance of counsel, and prior to retrial, Patterson attempted to exclude the fingerprint analysis evidence and expert testimony that was a key element in the prior conviction. (Multiple fingerprints “linked” to the defendant were found on the window of the Milligan's truck, the vehicle in which the detective was found shot to death.)

Patterson's argument was based on the premise that the community of fingerprint examiners was not large enough to “constitute a relevant scientific community for purposes” of evaluating general acceptance, a necessary element for the admission of expert testimony at trial. The fingerprints taken from “the scene” were not complete as none of the four latent prints met the standard eight points of similarity which is the generally accepted number necessary to conduct a proper analysis. At the first trial, Robert Folib, of the Boston Police Department, testified that while each individual print, taken by itself, did not satisfy the “magic number”, but since the individual latents were all believed to have been from one and the same hand, use of the prints as a group satisfied the requirement. If the prints had not been lumped together as being of the same hand, the examiner would have been unable to match a single latent print to those taken from Patterson.

Relying on Daubert v. Merrill Dow Pharmaceuticals, 509 U.S. 579 (1993), and Commonwealth v. Lanigan, 419 Mass. 15 (1994), the Supreme Judicial Court of Massachusetts concluded that while ordinarily latent fingerprint identification, namely the ACE-V method, meets the necessary level of reliability to admit its related expert testimony, evidence and analysis related to simultaneous impressions did not meet the “proven reliability” standard. Specifically, the State had failed to show that “the theory, process, and method of latent fingerprint identification could not be applied reliably to simultaneous impressions not capable of being individually matched to any of the fingers that supposedly made them.”

Reliability of latent fingerprint identification and ACE-V

Fingerprint experts around the world accept and apply the theory of latent fingerprint identification. (U.S. v. Mitchell, 365 F.3d 215, 222 (3d Cir. 2004); U.S. v. Llera Plaza, 188 F. Supp. 2d 549, 555, 566-67 (E.D. Pa. 2002).)

ACE-v is the standard methodology used throughout the US and many parts of the world. This method involves studying, methodically, three stages of ridge detail that may be visible in the latent impressions of friction skin. Level One detail studies the flow of the ridges and the gross details of visible patterns - at one time a study of Level One detail might have been called verification of class characteristics; Level Two detail looks at more intricate details of the finger's ridges such as forks formed at different ridge intersections, islands, and the like - formerly called individual ridge characteristics; Level Three detail studies the more intricate and microscopic characteristics including ridges, shape, width, and pore structure, if visible. An identification cannot be made on the basis of Level One detail, but the presence of sufficient Level Two detail can result in an identification. Level Three detail is particularly useful if Level Two detail is scant.

There are two distinct parts of the ACE-V process, one which is objective analysis of the prints, the other a subjective profile created from the examiner's expertise at fingerprint identification and comparison. While many jurisdictions used to require a minimum number of similar points before a positive identification between prints is confirmed, most now rely solely on the expertise of the examiner to serve as sufficient “proof” that a latent and full print are in fact a match.

What are simultaneous latent impressions?

Simultaneous latent impressions are the impressions left by multiple fingers from believed to be from the same hand left at the same time. A recurring question that resurfaced in Commonwealth v. Patterson was whether the process and theory of latent fingerprint identification, specifically the ACE-V method, meets the standards created in Daubert. Overcoming that hurdle is necessary to establish in order for expert testimony to be admitted that would explain the process of matching a latent impression with a “complete” fingerprint, at least in federal jurisdictions and in states that follow the model of the Federal Rules of Evidence as interpreted in Daubert. Specifically, the “prongs” that must be satisfied at the district court level in order for expert testimony to be admissible are: (1)“whether the expert would testify to valid scientific knowledge”, thereby fulfilling the “reliable” requirement; and (2) whether the testimony would help the jurors answer the questions at issue in the case, simply stated at relevance. The general practice of identifying crime scene latent fingerprints was deemed to satisfy the Daubert standards.

But that didn't end the inquiry in this case. Patterson required the State to meet a higher burden because the latent impressions were unable to be matched individually, therefore forcing the State to compare simultaneous, but incomplete latent fingerprint impressions to those of Terry Patterson. The court found that the State failed to prove the reliability of such a process.

BACKGROUND: A little more detail in the Patterson factual setting

Terry Patterson was convicted for the murder of a Boston police detective John Mulligan in 1995. Detective Mulligan was found shot to death in his vehicle outside a Walgreens where he moonlighted as a security guard. There were no eye witnesses to the murder, but persons in the area around the time of the killing observed two black men in the vicinity of the drugstore.

Patterson's conviction relied heavily on the use of ACE-V, the most widely used type of latent fingerprint technology, which a police expert testified placed Patterson at the scene of the murder. Simply, four fingerprint impressions were found at the scene of the crime, and the fingerprint examiner used those impressions to link Patterson to that crime.

However, that identification differed from the standard procedure because none of the four prints could be used alone. Instead, the examiner linked the similarities each finger possessed collectively to reach his conclusion. That conclusion was based on the practice called “identification by simultaneous impressions” which looks at the minor similarities between impressions that would be unallowable alone but accepted by some examiners. (“Simultaneous impressions” is the technical term for what is, simply, fingerprints believed to be made by multiple fingers from the same hand made at the same time.)

Daubert & Lanigan

Before Lanigan, Massachusetts followed the “general acceptance test” for admissibility of scientific evidence created in Frye v. United States, 293 F. 1013 (D.C. Cir. 1923), which looks at “whether the community of scientists involved generally accepts the theory or process.” This objective evaluation was intended to shield individuals from procedures that were not widely used or proven to produce effective results. In Lanigan, the Massachusetts court reestablished its dependency on “general acceptance” and the importance of that test but also allowed consideration of Daubert factors when “general acceptance” was not clearly established. For example, if the expert chosen to testify as to the general acceptance of the procedure used to fails to establish the reliability of the scientific evidence can go through a complete, five-factor Daubert analysis.

The five-factor test established in Daubert was designed to aid federal courts in determining whether expert testimony based on scientific, technical or other specialized knowledge could be admissible. Daubert purportedly implemented a more flexible admissibility standard to guide courts necessary in a society with constantly changing technology that allows law enforcement and the legal profession to access and analyze evidence through innovative procedures not previously developed. Those factors are: (1) whether the theory or technique can be and has been tested; (2) whether the theory or technique has been subjected to peer review and publication; (3) what is the known or potential rate of error of a particular scientific technique; (4) whether the relevant scientific community expresses a determination of acceptance of the theory or technique within that community. The inquiry is supposed to be a “flexible one” and does not require a talismanic application of the five factors. Further, Daubert inquiries focus on the “principles and methodology, not on conclusions that they generate because even reliable procedures can lead to incorrect results.”

Conclusion

Massachusetts did not set an unreachable goal for law enforcement and prosecutors, but rather, it established a reasonable expectation that the freedoms of its citizens will not be jeopardized by unreliable evidence. While fingerprint analysis is generally accepted within the scientific community, there are requisite levels of identifying detail that must be present in order for the evidence to meet the necessary standard prior to being admitted into evidence. The process of individualization by “simultaneous impressions” has not reached the necessary standard of trustworthiness.

Posted on April 5, 2006

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