WASHINGTON -- Law-enforcement officers around the country will be able to compare DNA genetic evidence taken from convicted felons and gathered in unsolved cases after the FBI switches on a national computer system today.
All 50 states will be linked to an FBI computer in Washington that contains genetic profiles of 250,000 convicted state felons and DNA profiles taken from evidence left at the scene of 4,600 unsolved cases, Dwight Adams, the chief of the FBI lab's scientific-analysis section, said yesterday.
The states have collected an additional 350,000 DNA samples from convicted felons but have yet to analyze them and enter the genetic profiles onto the computer database. "There's a backlog," Adams said.
Although all 50 states have laws authorizing blood sampling of some convicted felons to get DNA profiles, eight states have not begun collecting the samples, Adams said.
And though the federal government set up the national computer system to share the records, Congress has not passed a law authorizing the collection of DNA samples from federal felons. Proposed federal legislation would cover only violent felons, not white-collar criminals. But for now, the computer system contains only state records.
dams said that some states, such as Virginia, collect data from all felons including white-collar criminals, but other states take DNA samples only from criminals convicted of a restricted list of crimes . Every state covers sexual assaults, Adams said.
The DNA in the unsolved-case database is taken from crime scenes. DNA profiles can be obtained from semen collected after a rape, blood left on broken glass during a break-in or even bits of an assailant's skin caught under a victim's fingernails during an assault.
Since December the FBI has conducted an eight-state test of the system and has matched DNA evidence from almost 200 cases to specific individuals, Adams said. In the first such success, announced in December, a convicted felon in Illinois was matched to a Wisconsin rape case.
When local police labs take evidence from a convicted felon or crime scene they enter the DNA profiles into a state computer system. The states then decide which records are loaded into the FBI computer, known as the National DNA Index System.
When a state wants to make a comparison, it first checks locally, then statewide, then among nearby states and finally nationally in this computerized system. Each broader search takes more time.
If there are no matches between local evidence and the convicted-felon profiles, local authorities would then try to match their evidence with the profiles in the unsolved cases. This could link previously unrelated crimes and might help investigators find a culprit.
A match with a felon's profile is enough to provide probable cause to get a court order to get a new blood sample from that felon for comparison, Adams said.
The 1994 federal law that authorized the system set up an advisory board to set standards for scientifically valid DNA sampling. That board has recommended that police DNA laboratories be audited by outside specialists and that all DNA analysts be tested twice a year for proficiency.
Adams said private accrediting boards ensure that the labs meet those standards. Even police labs whose reliability has not been certified by outside accreditation can enter their DNA profiles into the national computer system and use it in investigations, he said.