Establishing a large DNA data bank using the PowerPlex 1.1 and 2.1 systems

Area of Science:

• Forensic Science
• Genetics
• Criminology

Background:

• The Virginia Division of Forensic Science recognized the need for a DNA Data Bank in the early 1990s.
• The data bank was intended for comparing convicted sex offender samples against unsolved cases to identify perpetrators.
• Legislation expanded to include all convicted offenders and juveniles tried as adults for felonies.

Purpose of the Study:

• To evaluate the effectiveness of the DNA Data Bank in aiding law enforcement.
• To assess the impact of technological advancements and data bank expansion on crime-solving capabilities.

Main Methods:

• Implementation of a DNA Data Bank for convicted offenders.
• Transition from Restriction Fragment Length Polymorphism (RFLP) to Short Tandem Repeat (STR) DNA analysis technology.
• Analysis of offender samples and forensic case samples for database matching.

Main Results:

• The DNA Data Bank has significantly aided law enforcement in solving crimes.
• An increase in offender sample analyses and unidentified suspect case analyses led to more DNA Data Bank hits.
• By December 31, 2000, the hit rate improved to one hit per 700 samples, a substantial increase from one hit per 2,900 samples in 1997.

Conclusions:

• The DNA Data Bank, particularly with the adoption of STR technology, has proven to be a valuable tool in criminal investigations.
• The expansion of the data bank and increased sample analysis have demonstrably improved its efficacy in identifying perpetrators.