State forensics lab now doing familial DNA testing
The Virginia Department of Forensic Science has developed the capability to perform a technique known as familial DNA searching. This application will expand DFS’ ability to assist in criminal investigations by searching its DNA database for a person or persons who may be closely related to an unknown individual, not in the database, whose DNA has been identified on an item of crime scene evidence and consequently is being sought as a suspect in a specific crime.
“It is vital that our law enforcement agencies have every available tool at their disposal to protect public safety and investigate the most violent crimes in the Commonwealth,” Gov. Bob McDonnell said. “This new technology will allow forensic experts to develop leads otherwise unavailable to law enforcement officers that can expedite the identification of criminals in certain cases and can get these offenders off the streets before any further loss of life or injuries to citizens occur.”
Familial DNA searching is currently being used in California and Colorado to provide law enforcement investigators leads to possible criminal suspects, and was instrumental in the 2010 capture of a murder suspect in California’s “Grim Sleeper” cases. The computer software required to perform a familial search of profiles in Virginia’s databank of convicted offender and arrestee DNA samples was developed by and provided to DFS without cost by the Office of Denver District Attorney Mitch Morrissey. The acquisition of the Denver software and the DFS laboratory personnel’s review to validate its suitability for searching Virginia DNA databank profiles followed requests from several local prosecutors to consider applying the technology to a number of unsolved crimes that occurred in the Commonwealth.
Virginia law requires that persons convicted of or arrested for certain specified crimes provide a sample of their DNA for inclusion in the state databank of DNA profiles. In a typical search of the database, a match is determined if a DNA profile in the databank is essentially the same as a DNA profile found on crime scene evidence. If a typical search does not result in a match, it is possible that a familial search could identify one or more database profiles that bear a strong similarity to the crime scene profile, suggesting that the persons who provided the DNA may be related. Further DNA analysis can be conducted to determine the likelihood of a family relationship before the names of potential relatives are provided to law enforcement officials for investigation. The success of identifying a lead to the perpetrator of an unsolved crime depends upon a parent, child, or sibling of the perpetrator having previously provided a DNA sample by law as a convicted offender or arrestee.
DFS has issued a policy for considering requests from law enforcement officials to conduct familial DNA searches in cases involving unsolved violent crimes against persons where other investigative leads have been exhausted and critical public safety concerns exist. In such a case, if crime scene evidence has yielded a DNA profile suitable for searching and law enforcement officials and prosecutors commit to further investigation if a potential relative is identified, the DFS director will direct that a familial DNA search be performed in accordance with departmental scientific protocols.