SOME EXAMPLES OF JUDICIAL DISPOSITIONS OF QUESTIONS RELATING TO FORENSIC SCIENCE EVIDENCE

Judicial Dispositions of Questions Relating to DNA Evidence

DNA typing has been subjected to the most rigorous scrutiny by the courts, presumably because its discriminating power is so great and so much is at stake when a suspect is associated to a crime scene only through DNA typing. Or perhaps because (at least some) modern courts or lawyers are more literate about science than they were in the past.54

Unlike many forensic techniques that were developed empirically within the forensic community, with little foundation in scientific theory or analysis, DNA analysis is a fortuitous byproduct of cutting-edge science. From the beginning, eminent scientists contributed their expertise to ensuring that DNA evidence offered in a courtroom would be valid and reliable,55 and by 1996 the National Academy of Sciences had convened two committees that issued influential recommendations on the use of DNA technology in forensic science.56 As a result, principles of statistics and population genetics that pertain to DNA evidence were clarified, the methods for conducting DNA analyses and declaring a match became less subjective, and quality assurance and quality control protocols were designed to improve laboratory performance.

Although some courts initially refused to admit the results of DNA testing because of perceived flaws,57 DNA evidence is now universally admit-

54

4 Faigman et al., op. cit., supra note 1, § 29:35, p. 41.

55

See, e.g., United States v. Yee, 134 F.R.D. 161 (N.D. Ohio 1991) (hearings held over 6 weeks featuring a total of 12 expert witnesses on the admissibility of DNA evidence); People v. Castro, 545 N.Y.S.2d 985 (N.Y. Sup. Ct. 1989) (hearings held over 12 weeks featuring a total of 10 expert witnesses on the admissibility of DNA evidence).

56

National Research Council, Committee on DNA Forensic Science. 1996. The Evaluation of Forensic DNA Evidence. Washington, DC: National Academy Press; National Research Council, Committee on DNA Technology in Forensic Science. 1992. DNA Technology in Forensic Science. Washington, DC: National Academy Press.

57

See Castro, 545 N.Y.S.2d at 999 (finding after a pretrial hearing that the “DNA identification evidence of inclusion” was inadmissible because “[t]he testing laboratory failed in several major respects to use the generally accepted scientific techniques and experiments for obtaining reliable results, within a reasonable degree of scientific certainty”). Decided a few years before the Daubert decision was handed down, Castro applied a modified Frye standard to determine the admissibility of DNA evidence. Later federal cases, both pre- and post-Daubert, held that alleged errors in handling and interpreting specific DNA samples would not render the evidence inadmissible as a matter of law, but should instead be raised at trial as factors for the jury to weigh in determining the credibility of the DNA evidence. See, e.g., United States v. Jakobetz, 955 F.2d 786, 800 (2d Cir. 1992); United States v. Trala, 162 F. Supp. 2d 336, 349 (D. Del. 2001), aff’d, 386 F.3d 536 (3rd Cir. 2004), vacated on other grounds, 546



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