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

In the early 1990's, the importance of establishing a DNA Data Bank of convicted sex offender samples for comparison to unsolved cases became apparent to the Virginia Division of Forensic Science to help identify potential perpetrators. Ultimately, through the expansion of the data basing law to include all convicted offenders and juveniles convicted of a crime that would be considered a felony if tried as an adult, the Division has successfully used the DNA Data Bank to aid the law enforcement community in solving crimes where the victim was unable to identify the perpetrator. As the number of offender sample analyses has increased, in combination with the number of analyses of cases where a suspect could not be identified, the number of DNA Data Bank hits has also significantly increased. Initially, in 1997, when the Division converted its DNA Data Bank program from the restriction fragment length polymorphism technology to the short tandem repeat technology, one offender hit occurred on average for every 2,900 convicted offender samples that were entered into the Data Bank. However, by December 31, 2000, one DNA Data Bank hit occurred on average for every 700 samples entered into the Data Bank.