Juries and crime labs: Correcting the weak links in the DNA chain

American Journal of Law and Medicine

Volumn 24, Issue 2-3, 1998, Pages 345-363

  McDonald, Ryan ^a  

^a STATE UNIVERSITY OF NEW YORK   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CRIMINOLOGY; DNA DETERMINATION; DNA FINGERPRINTING; DNA SEQUENCE; JURISPRUDENCE; LABORATORY TEST; LAW; NOTE; RESTRICTION FRAGMENT LENGTH POLYMORPHISM;

CRIMINAL LAW; DNA; DNA FINGERPRINTING; EXPERT TESTIMONY; FORENSIC MEDICINE; HUMANS; LABORATORIES; PREDICTIVE VALUE OF TESTS; QUALITY ASSURANCE, HEALTH CARE; UNITED STATES;

EID: 0031877395     PISSN: 00988588     EISSN: None     Source Type: Journal    
DOI: None     Document Type: Note

References (184)

1. See Tim Friend, Cutting Odds of Coincidental DNA Match, USA TODAY, May 3, 1996, at 4D. Databases of DNA [deoxyribonucleic acid] profiles now exist for the major races and ethnic groups, and studies of those databases can reveal how often a particular DNA fingerprint would appear. Comparing a suspect's DNA profile with a database from his or her own race will offer the most accurate calculation of the likelihood of a coincidental match . . . . Id.
2. See Tim Friend, Cutting Odds of Coincidental DNA Match, USA TODAY, May 3, 1996, at 4D. Databases of DNA [deoxyribonucleic acid] profiles now exist for the major races and ethnic groups, and studies of those databases can reveal how often a particular DNA fingerprint would appear. Comparing a suspect's DNA profile with a database from his or her own race will offer the most accurate calculation of the likelihood of a coincidental match . . . . Id.
3. See Eliot Marshall, Academy's About-Face on Forensic DNA, 272 SCIENCE 803, 804 (1996).
4. See Sue Rosenthal, My Brother's Keeper: A Challenge to the Probative Value of DNA Fingerprinting, 23 AM. J. CRIM. L. 195, 196 (1995) (outlining initial and recent challenges to DNA).
5. See Lisa Carrabino, Note, The Admissibility of DNA Typing and Statistical Probability Evidence, 24 SUFFOLK U. L. REV. 473, 474 (1995). "In order to determine the admissibility of DNA evidence, lawyers have expended much effort to conduct lengthy hearings and to call expert witnesses. . . . [T]he current debate surrounds the proper method forensic scientists should use to calculate the statistical probability of a coincidental match . . . ." Id. at 473-74 (footnote omitted).
6. See Lisa Carrabino, Note, The Admissibility of DNA Typing and Statistical Probability Evidence, 24 SUFFOLK U. L. REV. 473, 474 (1995). "In order to determine the admissibility of DNA evidence, lawyers have expended much effort to conduct lengthy hearings and to call expert witnesses. . . . [T]he current debate surrounds the proper method forensic scientists should use to calculate the statistical probability of a coincidental match . . . ." Id. at 473-74 (footnote omitted).
7. See Sharon Begley et al., Blood, Hair and Heredity, NEWSWEEK, July 11, 1994, at 24, 24.
8. See Armstead v. State, 673 A.2d 221, 226 (Md. 1996) (citing OFFICE OF TECHNOLOGY ASSESSMENT, GENETIC WITNESS: FORENSIC USES OF DNA TESTING 8 (1990)). DNA testing has been used as a forensic tool for nearly a decade. See id. After use by the United Kingdom in 1985, the Federal Bureau of Investigation (FBI) adopted it in 1988. See id.
9. See Begley et al., supra note 5, at 24. Since its first use in the United States in 1987, over 24,000 cases have involved DNA evidence. See id. In 30% of those cases, DNA has cleared people mistakenly suspected of crimes. See id. DNA has even freed over a dozen wrongly convicted men from prison. See id.
10. See Carrabino, supra note 4, at 474. Forensic scientists and the legal community have come to a consensus accepting the basic scientific theories that underlie DNA and DNA typing. See id. However, a current debate exists over the forensic methods scientists must use to calculate properly the statistical probability of a coincidental DNA match. See id.
11. See Edward J. Imwinkelried, Coming to Grips with Scientific Research in Daubert's "Brave New World": The Court's Need to Appreciate the Evidentiary Differences Between Validity and Proficiency Studies, 61 BROOK. L. REV. 1247, 1247 (1995) (noting that courts have feared situations in which scientific evidence would "cast a spell" over jurors prohibiting them from accepting testimony without criticism and giving the evidence undue weight).
12. See id. (quoting People v. Kelly, 549 P.2d 1240, 1245 (Cal. 1976)). In another case, the California Supreme Court characterized science as "a veritable sorcerer in our computerized society [who can] cast a spell" over the court system. People v. Collins, 438 P.2d 33, 33 (Cal. 1968).
13. See Imwinkelried, supra note 9, at 1247 (quoting United States v. Addison, 498 F.2d 741, 744 (D.C. Cir. 1974)).
14. See Janet C. Hoeffel, Note, The Dark Side of DNA Profiling: Unreliable Scientific Evidence Meets the Criminal Defendant, 42 STAN. L. REV. 465, 466 (1990) (citations omitted) which states: Although it usually takes many years for the engines of justice to churn out a personal injury suit or a criminal appeal, in less than two years the combined efforts of commercial laboratories and prosecutors have steamrolled the so-called "DNA fingerprinting" technique through the courts. The technique has been easy to sell. The current national obsession with crime-fighting and the apparent decrease in concern for individualized justice create a receptive environment for a cutting-edge technology, dazzling in its promise of identifying criminals with "virtual" or "99 percent certainty." Courts have lost all sense of balance and restraint in the face of this novel scientific evidence, embracing it with little scrutiny of its actual reliability and little concern for its impact on rights of individuals.
15. See id.
16. See Charles Edward Anderson, DNA Evidence Questioned: Bronx Judge Rules Lab Failed to Use Accepted Techniques, A.B.A. J., Oct. 1989, at' 18, 18 (discussing the problems with DNA evidence and reporting on a Bronx judge's decision to exclude DNA evidence because the lab failed to follow accepted scientific techniques); Robert D. McFadden, Reliability of DNA Testing Challenged by Judge's Ruling, N.Y. TIMES, Aug. 15, 1989, at B1 (discussing the same case in which the Bronx judge refused to admit DNA fingerprint evidence after hearing expert testimony criticizing the DNA lab procedures); Paul Reidinger, They Blinded Me with Science!, A.B.A. J., Sept. 1996, at 58, 58 (explaining how lawyers use the inherent uncertainty in scientific evidence to cast doubt on DNA evidence).
17. See Charles Edward Anderson, DNA Evidence Questioned: Bronx Judge Rules Lab Failed to Use Accepted Techniques, A.B.A. J., Oct. 1989, at' 18, 18 (discussing the problems with DNA evidence and reporting on a Bronx judge's decision to exclude DNA evidence because the lab failed to follow accepted scientific techniques); Robert D. McFadden, Reliability of DNA Testing Challenged by Judge's Ruling, N.Y. TIMES, Aug. 15, 1989, at B1 (discussing the same case in which the Bronx judge refused to admit DNA fingerprint evidence after hearing expert testimony criticizing the DNA lab procedures); Paul Reidinger, They Blinded Me with Science!, A.B.A. J., Sept. 1996, at 58, 58 (explaining how lawyers use the inherent uncertainty in scientific evidence to cast doubt on DNA evidence).
18. See Charles Edward Anderson, DNA Evidence Questioned: Bronx Judge Rules Lab Failed to Use Accepted Techniques, A.B.A. J., Oct. 1989, at' 18, 18 (discussing the problems with DNA evidence and reporting on a Bronx judge's decision to exclude DNA evidence because the lab failed to follow accepted scientific techniques); Robert D. McFadden, Reliability of DNA Testing Challenged by Judge's Ruling, N.Y. TIMES, Aug. 15, 1989, at B1 (discussing the same case in which the Bronx judge refused to admit DNA fingerprint evidence after hearing expert testimony criticizing the DNA lab procedures); Paul Reidinger, They Blinded Me with Science!, A.B.A. J., Sept. 1996, at 58, 58 (explaining how lawyers use the inherent uncertainty in scientific evidence to cast doubt on DNA evidence).
19. See COMMITTEE ON DNA TECH. IN FORENSIC SCIENCE, NATIONAL RESEARCH COUNCIL, DNA TECHNOLOGY IN FORENSIC SCIENCE 2 (1992) [hereinafter NRC REPORT].
20. See id. at 2-3.
21. See Rosenthal, supra note 3, at 197.
22. See A DICTIONARY OF GENETICS 60 (4th ed. 1990).
23. See Kamrin T. MacKnight, Comment, The Polymerase Chain Reaction (PCR): The Second Generation of DNA Analysis Method Takes the Stand, 9 SANTA CLARA COMPUTER & HIGH TECH. L.J. 287, 290 & n. 10 (1993).
24. See Hoeffel, supra note 12, at 470.
25. See H. ROBERT HORTON ET AL., PRINCIPLES OF BIOCHEMISTRY 10-8 to -10 (1993).
26. See Carrabino, supra note 4, at 475.
27. See id.
28. See id.
29. See id. at 476.
30. See Hoeffel, supra note 12, at 470. It is variations in the ordered structure of these bases along the DNA chain that determines which gene will be encoded and its form. See Rosenthal, supra note 3, at 198.
31. See Hoeffel, supra note 12, at 470.
32. See id.
33. Id.
34. See id.
35. See id.
36. See Carrabino, supra note 4, at 476. An individual's DNA will usually remain constant throughout his or her life. See Hoeffel, supra note 12, at 470. However, rare DNA mutatons do occur. See id.
37. See Carrabino, supra note 4, at 476.
38. See id. The sequence of most of the bases does not vary between individuals. See id. Hence, humans share most physical characteristics (e.g., two arms, two legs, etc.). See id.
39. See A.J. Jeffreys et al., Individual-Specific 'Fingerprints' of Human DNA, 316 NATURE 76, 78 (1985) (describing identical twins' DNA fingerprints as indistinguishable); Kevin C. McElfresh et al., DNA-Based Identity Testing in Forensic Science, 43 BIOSCIENCE 149, 153 (1993) (noting that only identical twins have similar DNA); Rosenthal, supra note 3, at 197 (same) .
40. See A.J. Jeffreys et al., Individual-Specific 'Fingerprints' of Human DNA, 316 NATURE 76, 78 (1985) (describing identical twins' DNA fingerprints as indistinguishable); Kevin C. McElfresh et al., DNA-Based Identity Testing in Forensic Science, 43 BIOSCIENCE 149, 153 (1993) (noting that only identical twins have similar DNA); Rosenthal, supra note 3, at 197 (same) .
41. See Hoeffel, supra note 12, at 470.
42. See id. The three million base pairs that vary among individuals are out of three billion such pairs in each DNA molecule. See id.
43. See id. Polymorphisms are variations that occur in a generally uniform fundamental structure. See Carrabino, supra note 4, at 476-77 & n.33.
44. See Carrabino, supra note 4, at 477; see also Hoeffel, supra note 12, at 471 (explaining that "the DNA profiling technique distinguishes among individuals by focusing on several highly polymorphic or 'hypervariable' sections of the DNA").
45. See Hoeffel, supra note 12, at 471.
46. See Carrabino, supra note 4, at 477.
47. See Marjorie Shaffer, NRC Report Calls DNA Testing an Accurate Way to Pinpoint Suspects, BIOTECH. NEWSWATCH, May 6, 1996, at 12, available in LEXIS, Genmed Library, Rxmega File.
48. See Begley et al., supra note 5, at 24.
49. See James Podgers, Decisions Split on DNA Admissibility: Differing Results Illustrate Impact of Supreme Court's Daubert Ruling, A.B.A. J., Dec. 1994, at 54, 54.
50. See Carrabino, supra note 4, at 477. There also exists a third method called "DNA base sequencing." See Hoeffel, supra note 12, at 475. Research labs use this method to discover the exact base sequence of the sample DNA strand. See id. It has not yet gained enough general acceptance to be used in DNA forensic testing. See id.
51. See Carrabino, supra note 4, at 477; Hoeffel, supra note 12, at 471 (noting that the ratio of labs using restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR) is three to one).
52. See Carrabino, supra note 4, at 477.
53. See Podgers, supra note 44, at 54. Forensic blood or semen is often dried, and technicians must extract it from clothing and various surfaces. See Hoeffel, supra note 12, at 472.
54. See Hoeffel, supra note 12, at 472.
55. See Podgers, supra note 44, at 54.
56. See Armstead v. State, 673 A.2d 221, 228 (Md. 1996) (describing the process by which restriction enzymes act as "chemical 'scissors'" to cut the DNA chain wherever a specific sequence of nucleotides exists); Podgers, supra note 44, at 54 (same). The same number and length of DNA fragments is produced in a particular individual each time a specific restriction enzyme is used. See Hoeffel, supra note 12, at 472. The enzymes would cut every individual's DNA in the same place if everyone's DNA were the same. See id. However, each individual's DNA is not the same. See id. Hence, the lengths of cut DNA segments vary among individuals. See id.
57. 52 See Podgers, supra note 44, at 54.
58. See id. This process is known as "electrophoresis." See Carrabino, supra note 4, at 478.
59. See Carrabino, supra note 4, at 478; MacKnight, supra note 19, at 296-97 (describing how electrophoresis causes DNA fragments to separate according to their size and weight).
60. See Podgers, supra note 44, at 54. This procedure, known as "Southern Blotting," is named after E.M. Southern, who developed this method at the University of Edinburgh. See Hoeffel, supra note 12, at 473. The procedure allows technicians to visualize the fragmented DNA patterns. See E.M. Southern, Detection of Specific Sequences Among DNA Fragments Separated by Gel Electrophoresis, 98 J. MOLECULAR BIOLOGY 503, 503-17 (1975) (describing the steps of the process).
61. See Podgers, supra note 44, at 54.
62. See id.
63. See id. The use of a "bar code" to describe this result may be misleading. Unlike a supermarket bar code, the DNA band pattern is very fuzzy. See Hoeffel, supra note 12, at 474.
64. See Podgers, supra note 44, at 54.
65. See Carrabino, supra note 4, at 479; Judith A. McKenna et al., Reference Guide on Forensic DNA Evidence, in REFERENCE MANUAL ON SCIENTIFIC EVIDENCE 273, 287 (Federal Judicial Ctr. ed., 1994) (noting the need for a substantial DNA sample for full and repeat testing, which may verify or refute the initial test). Many crime labs do not have the facilities to manage the radioactive reagents required by RFLP. See MacKnight, supra note 19, at 298-99.
66. See Carrabino, supra note 4, at 480.
67. See id. PCR testing works on small samples that are months or many years old. See id. The AmpliType DQ-alpha test kit is the prevailing PCR test. See MacKnight, supra note 19, at 306. DQ-alpha testing focuses on the polymorphic human leukocyte antigen DQ-alpha gene, identifying it with primers. See id.
68. See MacKnight, supra note 19, at 306. RFLP uses noncoding regions of the genome to detect variation between samples. See Rachel Nowak, Forensic DNA Goes to Court with O.J., 265 SCIENCE 1352, 1353 (1994). However, PCR analysis detects variation in actual genes, which show far less variation from one person to another than the noncoding regions. See id.
69. MacKnight, supra note 19, at 304.
70. See McKenna et al., supra note 60, at 287-88 (noting that PCR can make millions of copies of the DNA sample in only a few hours). By using PCR, technicians are able to produce a sufficient quantity of DNA fragments to perform DNA analyses. See LORNE T. KIRBY, DNA FINGERPRINTING: AN INTRODUCTION 75-76 (1990) (describing DNA amplification); McKenna et al., supra note 60, at 287-88 (explaining PCR amplification).
71. See LANSING M. PRESCOTT ET AL., MICROBIOLOGY 291-92 (2d ed. 1993); MacKnight, supra note 19, at 305.
72. See PRESCOTT ET AL., supra note 66, at 291.
73. See id.
74. See id.
75. See id.
76. See id.
77. See id.
78. See Karla K. Hotis, Note, The Admissibility of PCR-Based DNA Evidence: State v. Lyons, 37 JURIMETRICS J. 495, 496 (1997).
79. See NCR REPORT, supra note 15, at 65-67.
80. See MacKnight, supra note 19, at 315-19; cf. William C. Thompson & Simon Ford, DNA Typing: Acceptance and Weight of the New Genetic Identification Tests, 75 VA. L. REV. 45, 64-76 (1989) (discussing possible sources of contamination during RFLP analysis that are similar to those occurring during PCR analysis).
81. See MacKnight, supra note 19, at 314-15.
82. See CONCISE ENCYCLOPEDIA BIOLOGY 32 (Thomas A. Scott ed. & trans., 1996).
83. See MacKnight, supra note 19, at 314-15 (noting the possibility of contamination during PCR due to allele drop-out).
84. See id.
85. See Rosenthal, supra note 3, at 200.
86. See id.
87. See id.
88. See id. The reliability of the random population sample increases with the size of the sample population. See id. However, this method is still limited. See id. For example, if the test sample does not match 100 samples taken, all that can be said is that the test sample pattern does not occur in that 100-sample database. See id.
89. See id. at 200-01.
90. See Nowak, supra note 63, at 1353.
91. See id.
92. See id.
93. See id.
94. See id.
95. See id. Multiplying the "ceiling" frequencies for each of the subpopulations together produces the match probability for the whole profile. See id. In addition, the National Research Council (NRC) set the lowest figure for any allele calculation at five percent. See Peter Aldhouse, Geneticists Attack NRC Report as Scientifically Flawed, 259 SCIENCE 755, 755 (1993).
96. See Nowak, supra note 63, at 1352-53.
97. See id.
98. see Barry C. Scheck, DNA and Daubert, 15 CARDOZO L. REV. 1959, 1972 (1994); B. Devlin et al., Statistical Evaluation of DNA Fingerprinting: A Critique of the NRC's Report, 259 SCIENCE 748, 748 (1993) (criticizing the NRC's proposal).
99. see Barry C. Scheck, DNA and Daubert, 15 CARDOZO L. REV. 1959, 1972 (1994); B. Devlin et al., Statistical Evaluation of DNA Fingerprinting: A Critique of the NRC's Report, 259 SCIENCE 748, 748 (1993) (criticizing the NRC's proposal).
100. Nowak supra note 63, at 1354 (first and last alterations in original).
101. See, e.g., Commonwealth v. Lanigan, 596 N.E.2d 311, 314 (Mass. 1992) (holding the method of calculating the odds of a random DNA match unacceptable); State v. Vandebogart, 616 A.2d 483, 494 (N.H. 1992) (holding that evidence of a match is inadmissible because the FBI methods used to determine "population frequencies" were not generally accepted by the scientific community).
102. See United States v. Chischilly, 30 F.3d 1144, 1152 (9th Cir. 1994). Due to the "'raging controversy'" over DNA testing, the defendant argued that admission of "evidence of a match between his blood sample and semen found on the victim's clothing" was reversible error. Id.
103. See Friend, supra note 1, at 4D.
104. See Eric A. Fischer, DNA Ready to Clear, Implicate, COM. APPEAL (Memphis), Sept. 8, 1996, at 5B, available in LEXIS, News Library, Curnws File. Eric Fischer, Director of the Board on Biology at the NRC in Washington, D.C., recently served as the director of studies for the NRC's Committee on DNA Forensic Science. See id.
105. Shaffer, supra note 42, at 12 (quoting NRC Report).
106. See Marshall, supra note 2, at 803; Shaffer, supra note 42, at 12.
107. See id. This signals the return of the Product Rule. See id.
108. See Friend, supra note 1, at 4D. However, race-defined databases alone may be too simple. Larger populations might be composed of smaller genetically diverse subgroups. See R.C. Lewontin & Daniel L. Hartl, Population Genetics in Forensic DNA Typing, 254 SCIENCE 1745, 1746-47 (1991).
109. See Marshall, supra note 2, at 803.
110. Id.
111. See id. While the NRC report has won over one of the most prominent skeptics on the issue of DNA testing's validity, the problem now is "the lack of standardized, blind proficiency testing of DNA forensic labs." Id.
112. See Fischer, supra note 98, at 5B (stating that "[s]cientific questions should no longer keep DNA evidence from being accepted" and that "[i]t is time to welcome this powerful new tool fully into the courtroom").
113. See Marshall, supra note 2, at 803.
114. See id. (arguing that the "odds of laboratory error . . . may be more significant than the odds of a chance DNA match").
115. Fischer, supra note 98, at 5B.
116. See Crime Labs Get Ignored and Criminals Go Free, USA TODAY, Aug. 22, 1996, at 12A. Two of the nation's busiest labs, the Los Angeles and New York labs, are among the 60% that have not met the minimum accreditation standards of the American Society of Crime Lab Directors. See id.
117. See id.
118. See Peter Eisler, Calif.'s Crisis in a Word: O.J. Labs Point to Case in Their Campaign for More Funding, USA TODAY, Aug. 20, 1996, at 7A, available in 1996 WL 2066267.
119. See Case Closed: Mich. State Police Use DDC System to Solve Temp. Problems (Direct Digital Control), AIR CONDITIONING HEATING & REFRIGERATION NEWS, Aug. 30, 1993, at 20.
120. See Becky Beaupre, Backlogged Labs Put Justice on Hold, USA TODAY Aug. 20, 1996, at 7A. Raymond Holder grew up in a drug-infested neighborhood. See id. He worked hard as a prep cook to avoid the strife around him. See id. He swore he would never go to jail. See id.
121. See id.
122. See id.
123. See id.
124. See Lewis v. State, 451 S.E.2d 116, 117 (Ga. Ct. App. 1994). A lab technician took two blood samples from Lewis. See id. An officer then put the samples in an evidence locker. See id. A discrepancy arose concerning the locker numbers after a technician removed the samples. See id. The officer testified he believed he might have written down the wrong locker number. See id.
125. See State v. Ramos, No. 93-2448-CR, 1994 Wisc. App. LEXIS 978, at *2 (Wis. Ct. App. Aug. 10, 1994) (reversing and remanding for a new trial because defendant was deprived of the opportunity to prepare a full defense to the State's case, which was significantly enhanced by the blood splatters on defendant's shirt). The prosecution in this case was "livid" because the crime lab had missed the "extremely probative" blood on the shirt. See id. at *3.
126. See Michael Isikoff & Mark Hosenball, One Fed's War on the FBI, NEWSWEEK, Sept. 25, 1995, at 45, 45.
127. Frederic Whitehurst is a dedicated, by-the-book police officer and an expert in forensic chemistry. See id.
128. See id.
129. See id.
130. See id. For instance, after being confronted by Whitehurst with its sloppy methodology, the FBI had to change its findings on forensic tests done in the World Trade Center bombing case. See id.
131. See Marshall, supra note 2, at 804.
132. See id.
133. See Becky Beaupre, Some Say the Solution Lies in Lab Accreditation, USA TODAY, Aug. 21, 1996, at 9A. New York passed an act in 1994 mandating accreditation of the state's 15 crime labs by 1997. See id.; see also N.Y. EXEC. LAW § 995-b (McKinney 1996) (requiring the Commission on Forensic Science to establish a program of accreditation for all forensic laboratories in New York). As of 1996, eight had done so. See Beaupre, supra, at 9A.
134. See Beaupre, supra note 127, at 9A.
135. Id.
136. Nowak, supra note 63, at 1354.
137. See Beaupre, supra note 127, at 9A ("There is no question that (crime labs) need more oversight . . . . They need external control." (quoting James Starrs)).
138. See Fischer, supra note 98, at B5.
139. See supra Part II.C.1.a (explaining the process of declaring a DNA match through RFLP testing).
140. See D.H. Kaye, The Relevance of "Matching" DNA: Is the Window Half Open or Half Shut?, 85 J. CRIM. L. & CRIMINOLOGY 676, 679-80 (1995).
141. See id. at 679 & n. 15.
142. See id. at 680. Reproducibility studies allow technicians to find the likely extent of measurement error. See id. For example, a lab may compare DNA fragments obtained from a woman's vaginal swab with DNA from blood taken from the same woman. See id. This type of reproducibility study allows the lab to choose a wide enough "window" to result in a match when two samples come from the same source. See id.
143. See id. at 681.
144. See Lee v. State, 931 S.W.2d 433, 434-35 (Ark. 1996). The court considered blood samples "interchangeable items" that "require a more conclusive chain of custody than items of evidence which are subject to positive identification." Id. at 437.
145. See Smith v. State, 677 So. 2d 1240, 1245 (Ala. Crim. App. 1995). The defendant claimed DNA results were improperly admitted into evidence due to a "missing link" in the chain of custody of evidence collected by a rape-kit examination. See id.
146. See id.
147. See id.
148. See id.
149. See id. at 1246 (citing cases where courts have used the "reasonable probability" standard for the chain of custody).
150. See id. at 1247 "The purpose for requiring that the chain of custody be shown is to establish a reasonable probability that there has been no tampering with the evidence." Id. at 1245.
151. See id. at 1246 (quoting United States v. Anderson, 654 F.2d 1264, 1267 (8th Cir. 1981)). The Anderson court held that as long as it is persuaded that the evidence has been adequately safe-guarded, "the jury should be permitted to consider and assess it in light of surrounding circumstances." Anderson, 654 F.2d at 1267.
152. See Becky Beaupre & Peter Eisler, Crime Lab Crisis: Staff, Funding Haven't Kept Up with Caseload, USA TODAY, Aug. 20, 1996, at 1A.
153. See id.
154. See Eisler, supra note 112, at 7A.
155. See id.
156. People v. Simpson, No. BA 097211 (Cal. Super. Ct. Oct. 3, 1995); see also William C. Thompson, DNA Evidence in the O.J. Simpson Trial, 67 U. COLO. L. REV. 827 (1996) (discussing how the Simpson case revealed serious problems regarding the collection and handling of biological samples and the potential for cross-contamination of evidence).
157. See Beaupre & Eisler, supra note 146, at 1A.
158. See Snowden v. State, 574 So. 2d 960, 966 (Ala. Crim. App. 1990) (holding that "attacks on the validity of the underlying statistics go to the weight of such evidence, not its admissibility").
159. See id.
160. See Frye v. United States, 293 F. 1013, 1014 (D.C. Cir. 1923).
161. See Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579, 586 (1993).
162. See FED. R. EVID. 702.
163. See Scheck, supra note 93, at 1959.
164. See id.
165. See id. Under Frye, "[i]f a substantial controversy exists among reputable scientists, the technique is . . . not ready for court." Id. a. 1959-60. Judges must simply make judgments on the existence of a substantial controversy. See id. at 1960.
166. See id.
167. See id. at 1961. The opinion has been praised for making judges consider factors an empirical scientist considers when determining whether an experiment has been verified. See id. at 1959.
168. Imwinkelried, supra note 9, at 1252.
169. See Lori L. Swafford, Comment, Admissibility of DNA Genetic Profiling Evidence in Criminal Proceedings: The Case for Caution, 18 PEPP. L. REV. 123, 144-46 (1990) (remarking how DNA evidence is "unlike that presented with fingerprinting, footprint or bite mark evidence, [it] is highly technical, incapable of observation[] and requires the jury to either accept or reject the scientist's conclusion that it can be done" (quoting Andrews v. State, 533 So. 2d 841, 850 (Fla. Dist. Ct. App. 1988)).
170. Armstead v. State, 673 A.2d 221, 238 n.26 (Md. 1996) (quoting R.C. Lewontin, Letter, 372 NATURE 398, 398 (1994)).
171. See, e.g., Commonwealth v. Crews, 640 A.2d 395, 402 (Pa. 1994); cf. Armstead, 673 A.2d at 241 (stating that the better approach "is to treat the match and the statistics as inseparable components of DNA evidence").
172. See Armstead, 673 A.2d at 241-42.
173. One commentator notes that evidence of statistical probabilities does not remove from the jury the issue of identity "because jurors are free in any case to disregard or disbelieve expert testimony." Thomas M. Fleming, Annotation, Admissibility of DNA Identification Evidence, 84 A.L.R. 4th 313, 338 (1991). Therefore, juries must still fully deliberate the issue.
174. See supra Part IV.A-B (discussing match window and chain of custody issues).
175. See supra text accompanying notes 160-61 (describing the key question under a Daubert inquiry).
176. An example of an "essential" standard would be the use of acceptable chemical "primers" for PCR testing. See PRESCOTT ET AL., supra note 66, at 291-92.
177. "Reasonable certainty" denotes a standard less stringent than "beyond a reasonable doubt," but requires a formidable measure of proof. See, e.g., United States v. Amuny, 767 F.2d 1113, 1123 (5th Cir. 1985) (defining "reasonable certainty" as "requir[ing] something more than a showing of probable cause but something less than proof beyond a reasonable doubt" and stating that it is a "high standard").
178. See Begley et al., supra note 5, at 24 (noting that one commentator has referred to DNA evidence as "a fist on the scales of justice").
179. See Reidinger, supra note 14, at 59 (stating that "Daubert came to the right result; it's an anti-junk science opinion").
180. See supra Part II.D (discussing the reliability of DNA test results).
181. See Fleming, supra note 167, at 341-42 (discussing State v. Schwartz, 447 N.W.2d 422 (Minn. 1989), in which the Minnesota Supreme Court disallowed population frequency statistics associated with DNA typing "due to their exaggerated impact on the trier of fact" and acknowledged that juries will often "use [probability calculations] as a measure of the probability of the defendant's guilt or innocence" and otherwise give complex scientific evidence undue weight and deference).
182. See Imwinkelried, supra note 9, at 1247 (noting that courts have realized that scientific evidence often "cast[s] a spell" over jurors).
183. The Sixth Amendment provides, in relevant part: "In all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial, by an impartial jury of the State and district wherein the crime shall have been committed." U.S. CONST. amend. VI. For cases addressing the defendant's Sixth Amendment right in relationship to the admission of DNA evidence, see, for example, State v. Green, 867 P.2d 366, 372 (Kan. 1994) (holding that right to speedy trial is not violated by continuance issued to gather DNA evidence) and Armstead v. State, 673 A.2d 221, 224-25 (Md. 1996) (noting that trial court held that admission of DNA evidence did not deny defendant's constitutional right to confrontation; issue not raised on appeal).
184. For example, judges have discretion to exclude evidence if there is a "danger of unfair prejudice" on the jury that outweighs the probative value of the evidence. See FED. R. EVID. 403. Judges rule on the admissibility of such evidence as crime scene photographs, bloody articles of clothing and unauthenticated documents, which can have a devastating impact on the jury. See, e.g., United States v. Hilt, 981 F.2d 422, 423-24 (9th Cir. 1992) (holding that the prejudicial effect of photograph of defendant's automatic weapon also depicting several other weapons not owned by defendant outweighed its probative value; evidence created improper inference that defendant was a gun enthusiast).