“Fibers, hair, soil, wood, gunshot residue and pollen are only a few examples of trace evidence that may be transferred between people, objects or the environment during a crime.” See National Institute for Justice (NIJ), Trace Evidence.1
“Characteristics of race, body area, damage, decomposition, alteration (e.g., bleaching, dyeing), and whether a hair has been forcibly removed or naturally shed can be determined through human hair analysis. Comparisons of the microscopic characteristics in hairs can determine if a person can be included as a possible source of a questioned hair but cannot provide personal identification.” See Federal Bureau of Investigation (FBI), Handbook of Forensic Services, p 57.
For detailed analyses of hair and the many ways it is tested, identified, and used in the criminal justice system, see FBI, Forensic Science Communications.2 In addition, “the FBI has concluded that the [FBI forensic] examiners’ testimony in at least 90 percent of trial transcripts the Bureau analyzed as part of its Microscopic Hair Comparison Analysis Review [prior to 2000] contained erroneous statements.” FBI, FBI Testimony on Microscopic Hair Analysis Contained Errors in at Least 90 Percent of Cases (Ongoing Review). Since 2000, the FBI has routinely conducted mitochondrial DNA testing on hair, and “[t]he practice [of using microscopic hair comparison to link a criminal defendant to a crime] was deemed ‘highly unreliable’ in the 2009 National Academy of Sciences report on forensic science, Strengthening Forensic Science in the United States: A Path Forward. Nevertheless, some jurisdictions continue to use hair analysis where mitochondrial DNA testing is deemed too expensive, time consuming or is otherwise unavailable.” FBI, FBI Testimony on Microscopic Hair Analysis Contained Errors in at Least 90 Percent of Cases in Ongoing Review. Despite the National Academy of Sciences’ finding, the FBI found it “important to note that microscopic hair comparison analysis is a valid scientific technique[.]” FBI, FBI/DOJ Microscopic Hair Comparison Analysis Review.
Currently in Michigan, “[a]ny human hair characterization, screening or evaluation for DNA testing will be performed by the [Michigan State Police (MSP)] Biology Unit.” MSP, Trace-PM 11.0 Hair Analysis (2018). The information provided by MSP’s document Trace-PM 11.0 Hair Analysis states that MSP’s Trace Evidence Unit does not conduct “[m]icroscopic animal hair analysis/comparison.” Id. The document clearly indicates that any differentiation made between animal and human hairs must “be reported out as conclusions such as ‘apparent animal hairs observed’, or ‘possible human hairs observed.’” Id. See also MSP, Biology & DNA (summary of DNA testing performed by the Forensic Science Division’s Biology Unit in the multiple forensic laboratories in Michigan).
Committee Tip:
A number of committee members stated that microscopic hair analysis was rarely offered as evidence in cases with which they were familiar or in which they had participated. Another committee member’s discussion with an analyst at a Michigan State Police Forensic Science laboratory confirmed that a piece of evidence resembling a strand of hair or a piece of fiber was first evaluated to determine whether the piece of evidence was a hair or a fiber or some other material. Depending on the education and training of a laboratory analyst, further hair analysis might enable an analyst to determine whether the hair is a human hair or a canine hair.
Published opinions involving microscopic hair analysis have not been common in Michigan. The leading case and precedential authority in matters involving hair analysis is People v Vettese, 195 Mich App 235 (1992).3 According to the Vettese Court, “microscopic hair analysis satisfies the Davis-Frye[4] test for admissibility of scientific opinion testimony.” Id. at 240-241.
In Vettese, 195 Mich App at 241, hair-matching evidence was properly admitted to show “that the pubic hair found in the victim’s bed was similar in all relevant respects to the defendant’s pubic hair[.]” In addition to approving the hair-matching analysis as admissible scientific opinion testimony, the Vettese Court discussed the hair-matching analysis in terms of its relevancy under MRE 401. Vettese, 195 Mich App at 241. The Court noted that the matching hair placed the defendant in the group of persons who could have committed the crime. Id. The Court further found that statistical probability was unnecessary where the hair-matching analysis did not eliminate the defendant from the group of individuals from whom the hair could have originated. Id. Finally, because there existed additional substantial evidence of the defendant’s guilt, the Court concluded that the probative value of the hair-match was not substantially outweighed by the danger of unfair prejudice as prohibited by MRE 403. Vettese, 195 Mich App at 241.
Few published opinions involving microscopic hair analysis performed in the same manner as in Vettese have been issued since Vettese was released, but a number of unpublished opinions have been issued since Vettese. Unpublished opinions are not binding precedent, but they may be persuasive. MCR 7.215(C)(1).
One of those unpublished cases discusses microscopic hair analysis in detail. Watkins v State, unpublished per curiam opinion of the Court of Appeals, issued October 22, 2020 (Docket No. 348855), p 2. In that case, the Court summarized the testimony of two witnesses who were assigned to the serology and trace evidence area of Detroit’s crime lab and offered an explanation of the process. Id. at 2. The Court reiterated the witnesses’ testimony:
“[M]icroscopic hair analysis involve[s] the comparison of known and unknown hair samples on the basis of 15 different characteristics . . . . [K]nown and unknown hair could be microscopically similar and have a common origin . . . . [It is] not possible to say with reasonable scientific certainty that an unknown hair came from a known suspect.” Id.
In its study of the evidentiary value of microscopic hair analysis, the Watkins Court noted several factors the FBI discussed with regard to hair analysis:
“In 2013, the Federal Bureau of Investigation (FBI) agreed that examiners regularly overstated the conclusions that could be drawn from microscopic hair analysis evidence. It concluded that a forensic examiner could state that a known hair sample could be included or excluded as a possible source of unknown hair at a crime scene, but it was not possible to attach a probability to this possible inclusion or exclusion because the size of the pool of people who could have been a source for the hair was unknown.” Watkins, unpub op at 2-3.