DNA was first introduced as evidence in the United States criminal court system in 1986. In little more than a decade, DNA technology became an increasingly powerful forensic tool for identifying or eliminating suspects, when biological evidence such as saliva, skin, blood, hair or semen is left at a crime scene.
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First Use of DNA in Court
DNA was first used to solve a crime that occurred in England in 1986. In 1983 and 1986 in Narborough England, two young girls were raped and murdered. Over the course of the investigation, a 17-year-old local mental hospital employee confessed to committing the 1986 crime. While the two cases were very similar, the suspect would only confess to one. Authorities sought to use DNA testing to link the two crime scenes and thus implicated the suspect in the 1983 rape and murder.
The police were shocked to find that while the two crime scene samples matched each other, they did not match the suspect who confessed. After three and a half months in jail, the original suspect was released. This prompted the authorities to launch a mass screening of over 1400 townspeople. After the real perpetrator attempted to have someone else give "his" DNA sample, Colin Pitchfork was arrested and convicted for the 1983 rape and murder of Lynda Mann and the 1986 rape and murder of Dawn Ashworth.
State of California vs Parker
In 1996, Gerald Parker, then in a California prison on a parole violation stemming from a 1980 sentence for raping a child, was charged with the rape and murder of five women between December 1978 and October 1979 and the murder of a fetus during a rape in 1980. DNA samples from the crime scenes were run through California's sexual assault/violent offenders database, and four of the cases were found to have been committed by the same person.
After DNA tests linked Parker to the victims, he confessed to the crimes. He also confessed to a similar, fifth crime for which Kevin Lee Green had been wrongly convicted and had served 16 years in prison.
Additional Online Courses
- What Every First Responding Officer Should Know About DNA Evidence
- Collecting DNA Evidence at Property Crime Scenes
- DNA – A Prosecutor’s Practice Notebook
- Crime Scene and DNA Basics
- Laboratory Safety Programs
- DNA Amplification
- Population Genetics and Statistics
- Non-STR DNA Markers: SNPs, Y-STRs, LCN and mtDNA
- Firearms Examiner Training
- Forensic DNA Education for Law Enforcement Decisionmakers
- What Every Investigator and Evidence Technician Should Know About DNA Evidence
- Principles of Forensic DNA for Officers of the Court
- Law 101: Legal Guide for the Forensic Expert
- Laboratory Orientation and Testing of Body Fluids and Tissues
- DNA Extraction and Quantitation
- STR Data Analysis and Interpretation
- Communication Skills, Report Writing, and Courtroom Testimony
- Español for Law Enforcement
- Amplified DNA Product Separation for Forensic Analysts