The Science of Forensic Hair Comparisons and the Admissibility of Hair Comparison Evidence: Frye and Daubert Considered
||Max M. Houck, West Virginia University
Richard E. Bisbing, McCrone Associates, Westmont, IL
Tani G. Watkins, Michigan State Police Laboratory
Rockne P. Harmon, Alameda County District Attorney's Office
Admissibility of Hair Comparison Evidence
admissibility of hair comparison evidence will depend to a slight extent on
which rule is applicable and the interest by the trial judge in being a
gate-keeper. Any problems with admitting hair evidence can partly be solved if
the trial court is educated better by forensic scientists to the methodology
and reliability of hair comparison science. Forensic hair comparison evidence
fits the requirements of science and the rules of admissibility including Frye
Do Forensic Hair Comparisons Pass the Frye Test?
(U.S. v. Frye, 1923) is based on general acceptance in the scientific
community, which occasionally has been difficult to define (Green, 1992;
Thornton, 1994), it is still used by many jurisdictions in the United States. The microscopic examination of hair using the comparison microscope has been
the accepted standard technique for the examination and comparison of hairs for
approximately the past 60 years, and, as such, this technique has been accepted
by both State and Federal courts throughout the United States, in all U.S.
Territories, Canada and in many European and Asian countries.
standard usually involves a two-point question: Is the field in which the
underlying theory falls generally accepted in the relevant scientific
community? For hair comparisons, the answer is “yes.” Comparative biology,
including medicine and physical anthropology, has a long history of microscopic
identification and comparison dating back to the 18th century. Comparison is
the cornerstone of the majority of biology, both past and present. Microscopic
techniques, combined with studied experience, provide for a highly
discriminating means to examine and compare hair (Bisbing, 1982). A long
history of research in physical anthropology and forensic science detailing the
differences between peoples’ hair supports the credibility of the relevant
science (Bisbing, 1982; Hausman, 1925a; 1925b; Hausman, 1928; Houck, 2001;
Kirk, 1994; Trotter, 1930; Trotter, 1938).
of the identification and association of human hair, assuming a competent
comparison, is based on extensive experience by forensic laboratories around
the world since about 1932, including the FBI, Royal Canadian Mounted Police,
state, and local forensic laboratories, as well as private laboratories and a
body of peer reviewed scientific literature.
comparison has a generally accepted theory and basis for a reliable scientific
practice, based on literature in the Journal of Forensic Sciences, the Journal
of the Forensic Science Society (now Science and Justice), the Canadian
Society of Forensic Science Journal and other related peer-reviewed
scientific journals and publications, forensic science textbooks (for example,
Saferstein, 1996), and technical reference books (for example, Saferstein,
1982) used by forensic scientists. State and Federal forensic science agencies,
university forensic science programs, and private research institutes regularly
hold specialized training courses that teach hair comparison theory and
methodology (Proceedings of the International Symposium on Forensic Hair
Comparisons, 1985). An extensive body of literature exists for hair biology and
comparisons (Houck, 2001).
There is also a
collection of court decisions from all over the country where hair evidence has
been admitted over objection and upheld on appeal. Numerous case precedents
exist for admissibility of forensic hair examinations as a valid and reliable
science (U.S. v. Haskins, 1976; U.S. v. Cyphers, 1977; U.S. v. Brown, 1977;
State v. Watley, 1989; State v. Faricloth, 1990; State v. Payne, 1991; State v.
Bridges, 1992; Crawford v. State, 1992; People v. Wettese, 1992; Suggs v.
State, 1995; McCary v. State, 1995; Beam v. State, 1995; U.S. v.
procedures available that can produce reliable results and are they generally
accepted in the relevant scientific community? Specific techniques for hair comparisons
do exist based on previously cited literature, the curriculum of the courses
taught, the protocols that exist in most forensic science laboratories,
specifically those that are accredited or are undergoing accreditation, and the
experience of two generations of forensic scientists. Hair comparison tests can
be constructed to have discrete answers and are, therefore, testable. Forensic
hair examiners undergo testing during training and many take proficiency tests
once qualified (Peterson and Markham, 1995a, 1995b).
studies and research projects with published and peer reviewed reports have
demonstrated that given a limited number of questioned and known hair samples,
correct inclusions and exclusions are the rule rather than the exception
(Bisbing and Wolner, 1984; Lamb and Tucker, 1994; Gaudette, 1976; Gaudette and
Keeping, 1974; Strauss, 1983; Wickenheiser and Hepworth, 1990).