"Robert Melias became the first person convicted of a crime in England on the basis of DNA evidence in 1987" (Convicted by Juries, Exonerated by Science: Case Studies in the Use of DNA Evidence to Establish Innocence After Trial, National Institute of Justice, 1996).
A crime scene often is rich in information that reveals the nature of the criminal activity and the identities of those persons involved. Perpetrators and victims may leave behind blood, saliva, skin cells, hair, fingerprints, footprints, tire prints, clothing fibers, digital and photographic images, audio data, handwriting, and the residual effects and debris of arson, gunshots, and unlawful entry. Some crimes transcend borders, such as those involving homeland security, for which forensic evidence can be gathered (Strengthening Forensic Science in the United States: A Path Forward, National Academy of Sciences/National Institute of Justice-Sponsored, 2009).
The term "forensic science" encompasses a broad range of forensic disciplines, each with its own set of technologies and practices. Some of the forensic science disciplines are laboratory based (e.g., nuclear and mitochondrial DNA analysis, toxicology and drug analysis); others are based on expert interpretation of observed patterns (e.g., fingerprints, writing samples, toolmarks, bite marks, and specimens such as hair) (Strengthening Forensic Science in the United States: A Path Forward, National Academy of Sciences/National Institute of Justice-Sponsored, 2009).
The extensive use of biological evidence to identify victims and offenders has had a significant bearing, in recent years, on the course of law enforcement investigations, criminal court proceedings, and victim service provider issues. DNA evidence arguably has become the most well-known type of forensic evidence, probably because it can be uniquely identifying and because it is the genetic blueprint of the human body. For these reasons, DNA evidence has become a highly influential piece of the crime puzzle (The Future of Forensic DNA Testing: Predictions of the Research and Development Working Group, National Institute of Justice, 2000).
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. Responding officers and investigators should conduct their work at the crime scene as if it were the only opportunity to preserve and recover physical evidence. Keeping DNA evidence untainted until it has been collected and recorded is the most important aspect of managing the evidence. Maintaining a precise chain of custody for all DNA materials collected for testing is critical (DNA Evidence: What Every Law Enforcement Officer Should Know, National Institute of Justice, 2003). Forensic scientists also use DNA evidence to identify human remains, determine paternity, and study human populations and medical diseases.
For decades, the forensic science disciplines have produced valuable evidence that has contributed to the successful prosecution and conviction of criminals as well as to the exoneration of innocent people.Further advances in the forensic science disciplines will serve three important purposes:assist law enforcement officials in the course of their investigations to identify perpetrators with higher reliability;reduce the occurrence of wrongful convictions, which reduces the risk that true offenders continue to commit crimes while innocent persons inappropriately serve time;and enhance the Nation’s ability to address the needs of homeland security (Strengthening Forensic Science in the United States: A Path Forward, National Academy of Sciences/National Institute of Justice-Sponsored, 2009).
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.
This topical resource on Forensic Science contains the following information:
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.