NCJRS - National Criminal Justice Reference Service

Although DNA cannot determine a motive for a crime, it can be an important part of any law enforcement investigation, particularly one in search of an all-important lead. For example, DNA evidence may place a particular individual at a crime scene (What Every Law Enforcement Officer Should Know About DNA Evidence, National Institute of Justice, 1999). Forensic scientists also use DNA evidence to identify human remains, determine paternity, and study human populations and medical diseases.

Technological advances that have made it more reliable and efficient have increased the popularity of DNA evidence. For example, "the time needed to determine a sample's DNA profile has dropped from between 6 and 8 weeks to between 1 and 2 days." Future advancements may decrease this time to as little as a few hours or even a few minutes (Improved Analysis of DNA Short Tandem Repeats With Time-of- Flight Mass Spectrometry, National Institute of Justice, 2001).

Property crime offenders have high recidivism rates, their crime and violence can escalate, and property crime cases often go unsolved [1]. It has been estimated that each burglar in the top 10 percent of burglars commits more than 232 burglaries per year [2]. Several police departments in the United States are finding that they may be able to change these trends. When they analyze DNA from a burglary, they get evidence that often solves several other cases as well. And they are finding that biological evidence collected from property crime scenes can prevent future property crimes and more serious offenses (DNA in "Minor" Crimes Yields Major Benefits in Public Safety, National Institute of Justice, 2004).

There has also been an increased acceptance and use of DNA information in the courtroom. DNA evidence can help to convict the guilty, acquit the innocent, or exonerate those wrongly accused or convicted. This does not necessarily mean that DNA evidence alone can determine a verdict. DNA evidence is used often to corroborate eyewitness testimony or other evidence (Convicted by Juries, Exonerated by Science: Case Studies in the Use of DNA Evidence to Establish Innocence After Trial, National Institute of Justice, 1996). The increased use of DNA evidence also has made it important for victim service providers to become familiar with DNA terminology and DNA evidence collection, examination, and preservation procedures (Understanding DNA Evidence: A Guide for Victim Service Providers, Office for Victims of Crime, 2001).

To maximize the value of DNA evidence in the criminal justice system, the National Commission on the Future of DNA Evidence was chartered in 1997 and concluded work in 2001. The Commission identified three limitations to the full and effective use of DNA technology: (1) the current backlog of untested convicted offender database samples, (2) the lack of appropriate prioritization of database sample collection and testing, and (3) the limited use of DNA in non-suspect cases. To address these problems, the Commission in 1999 recommended the creation of federal grants that would facilitate the reduction of both collected and uncollected database samples, encourage the development of effective systems for the collection of those samples, and provide law enforcement agencies with direction and guidance to effectively use DNA in non-suspect cases. These recommendations subsequently led to NIJ's establishment in FY 2000 of two important initiatives: the Convicted Offender DNA Backlog Reduction Program and the No-Suspect Casework DNA Backlog Reduction Program. For FYs 2000-02 combined, Congress has appropriated more than $60 million to fund these programs to reduce or eliminate DNA laboratory backlogs in the U.S., populate the national database, and solve crimes.

To address the reach of forensic science across the entire justice system, NCJRS—on behalf of the U.S. Department of Justice's Office of Justice Programs—has compiled a list of resources to help provide a basic foundation of knowledge in forensic science.

[1]This quote is originally sourced as follows: Langan, P.A., and D.J. Levin, Recidivism of Prisoners Released in 1994, Washington, DC: U.S. Department of Justice, Bureau of Justice Statistics, 2002 (NCJ 193427): 1, 8; Crime in the United States 2002: 221, 223. Burglary had the lowest clearance rate of any Index crime. (Violent crimes are often more rigorously investigated, which explains why their clearance rate is higher than for property crimes.)

[2]This quote is originally sourced as follows: Chaiken, J.M. and M.R. Chaiken, Varieties of Criminal Behavior, Washington, DC: U.S. Department of Justice, National Institute of Justice, 1982 (NCJ 87680): 44.

Facts and Figures – Includes the latest information and statistics.
Legislation – A sample of links to online Federal and State legislation and testimony.
Publications – A sample of available resources.
Programs – Examples of State and local programs and initiatives available online.
Training and Technical Assistance – A sample of training and technical assistance opportunities available through nationally recognized agencies and associations.
Grants and Funding – Links to Federal funding opportunities.
Related Resources – Examples of nationally recognized agencies and organizations that provide services or information.

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