Mapping Public Policy for Genetic Technologies

Chapter 10. Criminal Justice

This chapter was prepared by Kelly Fox, NCSL policy specialist. NCSL staff contact is Donna Lyons, program director of NCSL’s Criminal Justice Program.

Information Contained in this Chapter

The Increasing Importance of Genetic Technology in the Criminal Justice System

DNA Evidence

Policy Implications

Regulation of Forensic Laboratories

Policy Implications

Genetic Databases

Policy Implications

State Activity

Conclusion

The Increasing Importance of Genetic Technology in the Criminal Justice System

More and more criminal trials hinge on intricate scientific evidence: the O.J. Simpson trial and the Oklahoma bombing trial provide examples. Progress in genetic technology has influenced criminal justice in three areas to date.

The admissibility of deoxyribonucleic acid (DNA) evidence in criminal trials. In the past this issue has been regulated by case law. Recently, however, legislation has been introduced that would encourage the use of DNA evidence.
Regulating forensic laboratories has become an issue in recent years. Regulation in the past has been minimal, bringing about the accusation by some that this has allowed the introduction of what some believe is inaccurate information.(also known as "junk science") into the courtroom.
Many states have begun to create genetic data banks that contain genetic samples from sex and violent crime offenders. This is a relatively new practice that is rapidly being adopted by many states.

DNA Evidence

DNA molecules contain properties that make DNA a good tool for identification. DNA typing is the process of comparing an identified person’s DNA with another sample. Each DNA sample is cut at a specific site and the two samples’ allelic patterns are compared. (Alleles are alternative forms of genetic locus, positions on a chromosome of a gene or another chromosome marker. Alleles are inherited separately by each parent. For example, at the locus for hair color there are alleles from each parent, which result in brown or blond hair color.) DNA typing is a complex process that includes 10 steps. The first step is breaking down the molecule to compare the allele patterns to determine whether there is a match between the known sample, the accused (also known as the electrophoresed) and the unknown sample—the sample found at the crime scene or on the victim.

After the analysis there are three possible results: exclusion, inconclusive and inclusion. The sample is excluded if the two samples do not match exactly. If the allelic bands are not visible for a comparison, the results are inconclusive and, finally, if the allelic patterns match exactly the results are an inclusion. (Inclusion means the DNA may have come from the same source.) Statistical analysis with population frequencies assist in determining whether the DNA was obtained from the same person. It is this statistical analysis that is controversial.

Once a match is found, the allele then is compared with genetic databases to calculate population frequencies for that particular allelic pattern. These population frequencies determine the likelihood that a random individual from the public could have left a tissue sample with that DNA at the crime scene. Most state courts have adopted the ceiling principle for determining population frequencies that is recommended by the Committee on DNA Technology in Forensic Science. The ceiling principle is a conservative measure that calculates population frequencies independently of race. Reportedly, this calculation reduces the chance that population substructures undermine results. Population substructures occur when one race or ethnic group has a specific set of alleles that does not appear with the same frequency in the rest of the population. If compared directly with the general population, the probability of another person having that allelic pattern is extremely low and may unduly prejudice a group of individuals.

Determining the admissibility of this evidence typically has been left to the courts and their application of Frye vs. United States and Daubert vs. Merell Dow Pharmaceuticals Inc. The Frye test also is known as the general acceptance test. This test requires the scientific community, as the reviewing body, to determine if proposed scientific evidence is generally accepted within the scientific community and should be viewed as reliable. This involves a two-tiered approach. First, there must be acceptance of the scientific theory within the scientific community. Secondly, the techniques used to apply this theory must be accepted within the scientific community. At least 15 states apply the Frye test when deciding whether to admit scientific evidence. Matching evidence generally is accepted under Frye. However, the calculation of population frequencies has been disputed in the past, creating a situation in which the matching evidence is admitted but the statistical evidence—the population frequencies—is not. Over time, more and more courts have admitted both tests. Those courts that did not allow the statistical analysis reportedly did so because the tests were not conducted under the conservative ceiling principle.

In Daubert the Supreme Court held that Federal Rule 702 overrules the Frye test for admissibility of scientific information. The federal rule states that, if the scientific information in question will assist the trier of fact to understand evidence, he or she may offer an opinion. The judge may decide if the information is admissible under Daubert by examining whether the information is relevant to the case, if the individual is qualified as an expert, and whether the information will assist the trier of fact. Critics have argued that Daubert is more lenient than Frye and, as such, has led to the introduction of "junk science." Proponents argue that those who feel the evidence is questionable and is not approved within the scientific community should simply approach this evidence with the same vigorous cross- examination and presentation of stronger evidence to the contrary. Courts in at least 10 states follow the Daubert decision.

Policy Implications

The U.S. criminal justice system is based on the premise that an individual is innocent until proven guilty. This premise must be remembered when drafting legislation regarding the admissibility of evidence. If state lawmakers are interested in regulating or encouraging the use of genetic information in criminal trials, the interests of the victim, the accused and the state need to be addressed.

If state legislatures are to consider legislation on DNA information, then the lessons learned from the court’s application of Frye and Daubert should be remembered. Although the practice of matching alleles is relatively accepted within the scientific community and the legal community, the different approaches to statistical analysis cause the practice to not be as readily accepted by either community. Should the legislature mandate under which criteria scientific evidence will be accepted in order to create uniformity and standards within the system? If so, is it more important to adhere to more conservative standards (as in Frye) with the hopes of preventing an innocent person from being punished for a crime he or she did not commit? Or, is it more important to adhere to more lenient standards that would allow the trier of fact to hear more evidence before rendering a judgment?
Should the courts determine which evidence the scientific community generally accepts or should the legislature intervene by outlining precisely which evidence is admissible and which is not?

Regulation of Forensic Laboratories

Related to the issue of admissibility is whether the forensic laboratories should be regulated as to the theories and practices that are used. In 1992, the National Academy of Sciences examined DNA typing and determined it was reliable. However, the academy urged better quality control within laboratories that carry out this analysis and urged courts not to allow broad analyses from the data or to use the data to make positive identifications.

Policy Implications

Should laboratories be regulated by the legislature to ensure strict standards are followed? Although the police and prosecutors argue there is not a quality control problem in laboratories, defense attorneys argue that studies have been conducted that show that private laboratories have made errors in one in 50 samples examined, making statistical analysis meaningless. The police and prosecutors agree that errors can occur but believe DNA testing will not result in false identification if testing procedures are always followed and the results interpreted by competent experts.

Genetic Databases

The DNA database is a useful tool for police and prosecutors who are faced with a crime that involves a suspect who has a previous conviction for a similar crime. If the individual’s genetic information has been stored in the database, the police can determine if they should pursue a case against the suspect. Concerns arising from this database include:

Unfair discrimination against individuals previously convicted of violent crimes.
Unwarranted intrusion into one's right to privacy and bodily integrity.
The potential that an early match will prevent or cloud the police department’s judgment to pursue a case against additional suspects.

Policy Implications

There are two areas that should be examined when drafting legislation.

If a database is created, who should pay for the database? Currently such databases are being funded through the state budget or by a fee charged to the criminal by the court as part of restitution.
What steps should be taken to ensure the accused’s rights are not violated?

State Activity

As more courts are admitting genetic information as evidence at trial, legislation is being introduced to regulate this evidence. In 1997, 18 states introduced legislation regulating the use of DNA evidence in trials, the use of genetic information to monitor sexual and other violent offenders and assessing fees for DNA samples collected (see table 10-1). Since the early 1990s, 27 states have passed legislation that adopts the DNA identification database (see table 10-2). In 1997, several states considered establishing DNA databases for individuals who are convicted of sexual and other violent offenses. Arkansas and Wyoming passed legislation to adopt DNA identification databases. In addition, the FBI has established the federal CODIS program as a genetic database. The CODIS program encourages state participation in the CODIS program by awarding federal grants to assist states to set up and run the program. Access to this database gives states access to genetic information nationwide.

Conclusion

Although progress in scientific and genetic technologies has increased the amount and kinds of information available to those who investigate and prosecute alleged criminals, enthusiasm for its use cannot eclipse the rights of the accused. Legislation needs to take into account the rights of the alleged criminal, as well as the need to find and convict those who do commit crimes. The new genetic and scientific information should be technologically sound and generally accepted within the scientific community as viable evidence.

To Table 10-1. State Criminal Justice Legislation Related to Genetics Introduced in 1997
To Table 10-2. DNA Databases Legislation Introduced in 1997

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