The 28 cases examined by the study raise issues that have policy implications for the criminal justice system. The most significant are presented below.¹

Reliability of Eyewitness Testimony

In the majority of the cases, given the absence of DNA evidence at the trial, eyewitness testimony was the most compelling evidence. Clearly, however, those eyewitness identifications were wrong. In one of the clearest examples of eyewitness testimony overwhelmingly influencing the jury, the Pennsylvania Intermediate Court of Appeals commented on the evidence in the Dale Brison case:

The Commonwealth's evidence consisted primarily of the victim's identification testimony. However, the victim's stab wounds in addition to the weather and reduced visibility may well have affected the victim's ability to accurately view her assailant, and thus, she may have been prompted to identify appellant merely because she remembered seeing him in the neighborhood. Moreover, the victim did not specifically describe any of her assailant's facial characteristics to the police. There was also no conclusive physical evidence, aside from a single hair sample which may have been consistent with any male of [A]frican[A]merican descent, linking appellant to the crime.²

This points conclusively to the need in the legal system for improved criteria for evaluating the reliability of eyewitness identification.

In Neil v. Biggers,³ the U.S. Supreme Court established criteria that jurors may use to evaluate the reliability of eyewitness identifications. However, the reliability of eyewitness testimony has been criticized extensively in the literature.⁴ In a recent interview, Dr. Elizabeth Loftus, one of the best-known critics of the reliability of eyewitness identification, commented on the role of DNA testing in exonerating innocent persons who served time in prison. Dr. Loftus noted that a significant factor is the potential susceptibility of eyewitnesses to suggestions from police, whether intentional or unintentional. As reported, Dr. Loftus stated that there is "pressure that comes from the police [who] want to see the crime solved, but there is also a psychological pressure that is understandable on the part of the victim who wants to see the bad guy caught and wants to feel that justice is done."⁵

Dr. Loftus has recommended more open-ended questioning of victims by the police to avoid leading questions. In addition, Dr. Loftus and others have recommended use of expert testimony regarding the pros and cons of relying on eyewitness testimony.⁶

Reliability of Non-DNA Analyses of Forensic Evidence Compared to DNA Testing

In many of the study cases, according to documentation examined and those interviewed, scientific experts had convinced juries that non-DNA analyses of blood or hair were reliable enough to clearly implicate the defendants. Scientific conclusions based on non-DNA analyses, however, were proven less discriminating and reliable than those based on DNA tests. These findings point to the need for the scientific community to take into account the reliability of non-DNA forensic analyses vis-à-vis DNA testing in identifying the sources of biological evidence.

In a recent habeas corpus hearing in a murder case, a U.S. district court held that expert testimony on microscopic hair comparisons was inadmissible under the Daubert standard.⁷ The court cited studies documenting a high error rate and found that there are no accepted probability standards for human hair identification. The court ruled that in this case the expert's hair testimony was "imprecise and speculative, and its probative value was outweighed by its prejudicial effect."⁸

Competence and Reliability of DNA Laboratory Procedures

One of the lasting effects of the O.J. Simpson case will likely be greater scrutiny by defense lawyers of the prosecution's forensic DNA evidence presented in criminal cases. In the Simpson case, the defense, in essence, put the crime laboratory on trial. The National Research Council (NRC) report entitled DNA Technology in Forensic Science states

There is no substantial dispute about the underlying [DNA] scientific principles. However, the adequacy of laboratory procedures and the competence of the experts who testify should remain open to inquiry.⁹

The NRC report recommends some degree of standardization to ensure quality and reliability. The report recommends that each forensic laboratory engaged in DNA testing must have a formal, detailed program of quality assurance and quality control. The report also states:

Quality assurance programs in individual laboratories alone are insufficient to ensure high standards. External mechanisms are needed to ensure adherence to the practices of quality assurance. Potential mechanisms include individual certification, laboratory accreditation, and state or federal regulation.¹⁰

As recently reported by the American Society of Crime Laboratory Directors, 32 public DNA laboratories have been accredited. In addition, one private laboratory is accredited.¹¹

Whether laboratories that conduct DNA tests possess the requisite qualifications has significant cost implications for the criminal justice system in terms of reducing the number of redundant DNA tests. In many cases in this study, both prosecution and defense obtained independent DNA tests of the biological stain evidence. Although independent examinations are common in areas that are more open to interpretation (e.g., mental fitness for trial), DNA testing, for exculpatory purposes, should be performed in a qualified laboratory, and the results, if they exculpate the suspect, should be accepted by both parties. Such acceptance would seem more likely if DNA tests were performed by laboratories that all parties agreed were qualified.

Preservation of Evidence for DNA Testing

In some States, sentenced felons may experience difficulty obtaining access to evidence for DNA testing. With an increasing volume of criminal cases, some police agencies destroy evidence when defendants have exhausted their appeals. Even when defendants obtain access to the evidence, it may be too deteriorated for DNA testing. In some of the study cases, insufficient evidence prevented laboratories from conducting Restriction Fragment Length Polymorphism (RFLP) testing, but Polymerase Chain Reaction (PCR) testing was still possible.

Preserving biological stain evidence and maintaining the proper chain of custody of the evidence are essential for successful DNA testing.¹² At the trial stage, however, the U.S. Supreme Court has ruled that unless a criminal defendant can show bad faith on the part of the police, failure to preserve potentially useful evidence does not constitute a denial of due process of law.¹³ After a defendant's conviction, prosecutors are not required by constitutional duty to preserve evidence indefinitely. As noted earlier, in Daye, the evidence was about to be destroyed when his attorney filed to stay the destruction to conduct what turned out to be an exculpatory DNA test.

Training in DNA Forensic Uses

The introduction of DNA technology into the criminal trial setting is likely to create uncertainty, spawned in part by the complexity of the technology, and also to possibly generate unrealistic expectations of the technology's power in the minds of some or all of the players: prosecution, defense, judges, and jurors. The scientific complexities of the technology may influence all parties to rely more heavily on expert testimony than on other types of evidence.

As the use of DNA technology becomes more widely publicized, juries will come to expect it, like fingerprint evidence. This will place more pressure on prosecutors to use the technology whenever possible, especially as the cost decreases. Prosecutors must be trained on when to use the technology and how to interpret results for the jury.

When the prosecution uses DNA evidence, the defense will be forced to attack it through expert testimony. The defense must rebut the persuasiveness of the evidence for the jury. As stated in the NRC report, "Mere cross examination by a defense attorney inexperienced in the science of DNA testing will not be sufficient."¹⁴ Thus, defense counsel as well as the prosecution and judiciary must receive training in the forensic uses of DNA technology.

Third Party Consensual Sex Sources

The primary objective of the defense in using DNA testing in rape cases is to show that the defendant is excluded as the source of the semen evidence. Even when exclusion is established, the prosecution may be motivated, as in Davis, to eliminate as suspects any and all consensual sex partners as sources of semen in rape cases. During the first trial of Gerald Wayne Davis, the prosecution contended that the semen in the victim came from Davis. After DNA testing had excluded Davis as the source of the semen, the prosecution contended, in the second trial, that Davis could have still raped the victim but not ejaculated and that the semen in the victim could have come from the victim's fiancé just prior to the rape. The prosecution never obtained a blood sample from the fiancé because he died before the second trial.

A question under the law is whether third parties can be compelled to provide biological evidence for DNA testing. In some cases, the government refused to release defendants after exculpatory DNA results until third parties were located and tested. Kerry Kotler was held for an additional year after his exculpatory DNA test so the government could test the victim's husband. Edward Honaker was held for an additional 9 months after his exculpatory DNA test so the government could test the victim's boyfriend and "secret lover."

Multiple-Defendant Crimes

The DNA technology used to analyze biological evidence from crime scenes must not be oversold as an exculpatory tool-it does have limitations. Multiple-suspect crimes present a particular problem for use of DNA identification as a crime-solving tool. In multiple-suspect sexual assaults without eyewitnesses, such as a rape-murder, it is possible that only one of the suspects ejaculated in, or even raped, the victim. In such cases, DNA testing of semen would seem likely to exculpate one or more of the suspects. This type of situation presents a real dilemma for police and prosecutors. Because of exculpatory DNA tests on semen and possibly other exculpatory evidence (e.g., an alibi, lack of other physical evidence), pressure mounts on prosecutors to release one or more of the suspects. The only other evidence against them may be the testimony of a suspect who is matched to the crime by DNA analysis.

In Dabbs, for example, the victim testified that she was dragged into an alley and raped by one man while two other men held her down. The police arrested Dabbs on the basis of identification of him by the victim, a distant cousin. The other alleged assailants were never identified or arrested. The DNA test showed that the semen evidence from the victim did not match Dabbs. One theory of the case, however, was that Dabbs participated in the crime but was not the rapist. The prosecutor ultimately dismissed the original indictment against Dabbs because of the DNA results and the reluctance of the victim to testify at a new trial.

Posttrial Relief

Most States have a time limit on presenting evidence newly discovered after trial, conviction, and sentencing. The reason for limiting the time to file appeals based on new evidence is to ensure the integrity of the trial process and jury verdicts. Many DNA issues in the study cases were not raised until the postconviction stages. Absent constitutional issues, many State procedures, as in Virginia,¹⁵ may preclude consideration of new exculpatory DNA evidence at postconviction stages. Some of the study defendants, after receiving exculpatory DNA results, were released only by agreement of the prosecutor; sometimes they needed a pardon by the governor.

Some States, such as Oregon, permit judges to use discretion to waive new-evidence rules and set aside verdicts or order new trials.¹⁶ Thus, some States may allow an out-of-time motion for a new trial when newly discovered evidence clearly serves the interests of justice.¹⁷

At postconviction stages, appointment of counsel and payment for DNA testing become issues for indigents. While some appeals courts have ordered State-paid DNA testing for indigents where justified (e.g., where the overall case against the defendant is weak), other court rulings deny such relief, especially where the exculpatory value is speculative.¹⁸ As DNA testing to exculpate convicted persons becomes more widespread, States need to consider these issues.

Future DNA Forensic Uses

The momentum is growing, spurred in part by the public's education from the Simpson trial, for DNA testing in criminal cases. Juries may begin to question cases where the prosecutor does not offer "conclusive" DNA test results if the evidence is available for testing. More defense attorneys in court-appointed cases may file motions for DNA testing and request the State to pay for the tests (this issue may also be raised as a Brady motion for the prosecutor to conduct the tests).

The shift will be for more DNA testing in pretrial stages. Prosecutors should find that DNA testing is as helpful to them as to the defense in excluding suspects early in the investigation. This will enable the police and prosecution to save money in the long run by focusing investigations in more fruitful directions.

In Britain, mass DNA screening in search of suspects has, in recent years, produced arrests in several highly publicized cases. The most recent case involved the rape-murder of a 15-year-old South Wales girl.¹⁹ The South Wales constabulary obtained saliva swab samples from over 2,000 men who lived in the vicinity of the murder. Police went door-to-door inviting men to a makeshift laboratory to submit the samples. The saliva samples were used to develop DNA profiles to compare to the DNA profile obtained from the assailant's semen.

British law does not permit compulsory sampling, but the police made it clear that anyone who refused would become the subject of intense police investigation. A 19-year-old resident of the victim's neighborhood was arrested when his saliva sample was the only one of the thousands taken that could not be eliminated.

Such DNA dragnet methods, while employed sparingly in Great Britain, may increase as the ease and affordability of DNA testing improves. It is unlikely that such mass-testing methods would gain favor in the United States. Constitutional protections against self-incrimination and unreasonable searches and seizures, as well as the American public's zealous protection of privacy rights, would preclude such DNA dragnet practices from being implemented in this country.

Endnotes for Chapter III

1. This report does not discuss the issue of government misconduct because it is not particularized to the use of DNA technology. Beyond the limited instances noted in this report, enough examples of government misconduct in the criminal justice system exist in the popular media for government officials to be well aware of the problem.  [Back]

2. Commonwealth v. Brison, 618 A.2d 420,425 (Pa. Super. 1992).  [Back]

3. Neil v. Biggers, 409 U.S. 188, 199200 (1972) (factors include accuracy of the witness' prior description of the defendant, opportunity to view the defendant at the time of the crime, level of certainty demonstrated, witness' degree of attention, and time between the crime and the confrontation).  [Back]

4. Loftus, Elizabeth, and D. Fishman, "Expert Psychological Testimony on Eyewitness Identification," Law and Psychology Review, 4 (1978):87-103 (lack of reliability on cross-racial identification); Loftus, Elizabeth, and W. Wagenaar, "Ten Cases of Eyewitness Identification: Logical and Procedural Problems," Journal of Criminal Justice, 18 (1990):291-319 (witnesses can be induced to point to the suspect after subtle suggestion on the part of the investigator); and Cutler, Brian, et al., "The Reliability of Eyewitness Identification: The Role of System and Estimator Variables," Law and Human Behavior, 11, 3 (1987): 233-258 (level of stress experienced during crime may affect identification).  [Back]

5. "DNA Testing Turns a Corner as Forensic Tool." Law Enforcement News (October 15, 1995):10.  [Back]

6. Loftus, Elizabeth, and N. Schneider, "Judicial Reactions to Expert Testimony Concerning Eyewitness Reliability" UMKC Law Review, 56, 1 (1987):1-45; and Handberg, Roger, "Expert Testimony on Eyewitness Identification: A New Pair of Glasses for the Jury," American Criminal Law Review, 32, 4 (Summer 1995):1013-1064.  [Back]

7. Williamson v. Reynolds, 904 F. Supp. 1529 (E.D. Okl. 1995).  [Back]

8. Id., at 1558. The National Research Council report, DNA Technology in Forensic Science, notes that, in contrast to microscopic hair comparison, with the advent of DNA technology, the use of hair as an individual identifier will become more common. National Research Council, National Academy of Sciences, DNA Technology in Forensic Science, Washington, D.C.: National Academy Press, 1992:158.  [Back]

9. DNA Technology in Forensic Science, supra note 8, at 145-146.  [Back]

10. d., at 16. In its 1996 DNA report, The Evaluation of Forensic DNA Technology (National Academy Press, Washington, D.C.), the National Research Council reaffirmed this position (page 3.12). The DNA Identification Act of 1994 (Public Law 103-322) also provides for a DNA advisory board to set standards for DNA testing.  [Back]

11. Telephone conversation with Manuel Valdez, treasurer, American Society of Crime Laboratory Directors, March 8, 1996. (More than 100 public laboratories perform DNA tests.)  [Back]

12. See "Oops! We Forgot to Put It in the Refrigerator: DNA Identification and the State's Duty to Preserve Evidence," The John Marshall Law Review, 25 (1992):809-836.  [Back]

13. Arizona v. Youngblood, 109 S. Ct. 333, 337 (1988). The Supreme Court also stated that "police do not have a constitutional duty to perform any particular tests."  [Back]

14. Supra note 9 at 160.  [Back]

15. Virginia Supreme Court Rules, Rule 3A: 15(b).  [Back]

16. An Oregon judge recently released Laverne Pavlinac and John Sosnovske from prison, where they had served 5 years after being convicted of murdering a young woman. The judge set aside their convictions because Keith Hunter Jesperson, a convicted serial killer, pleaded guilty to the murder for which the couple was convicted. See The New York Times, November 28, 1995:28.  [Back]

17. Tuffash v. State, 878 S.W. 2d 197 (Tex. App. 1994). This case involved perjured trial testimony from Fred Zain, the State's forensic serologist.  [Back]

18. See State v. Thomas, 586 A. 2d 250 (N.J. Appl. Div. 1991); and Commonwealth v. Brison, 618 A. 2d 420 (Pa. Super. 1992). Compare to People v. Buxon, 593 N.Y.S. 2d 87 (App. Div. 1993).  [Back]