With civil libertarians crying foul, seven states have authorized police to take DNA samples from those arrested for - but not convicted of - certain crimes.
Every state takes DNA samples from convicted sex offenders and at least 43 states take samples from other serious felons, according to the National Conference of State Legislatures, which tracks state laws. But five states - California, Louisiana, Minnesota, Texas and Virginia - now take DNA samples from some arrestees as well.
Kansas and New Mexico passed authorizing legislation this spring and will begin arrestee sampling next January.
Officers commonly take the samples by using cotton swabs to collect saliva. The samples are used to try to solve "cold cases" by comparing them to biological evidence found at crime scenes. DNA profiles, or computerized snapshots of the samples, are stored in local, state and federal databases, allowing law enforcers to compare information.
Last January, President Bush signed the DNA Fingerprinting Act, which allows authorities to collect DNA "fingerprints," or samples, from anyone arrested on any federal charge. Federal sampling has not yet begun, said Ann Todd, a spokeswoman for the FBI laboratory in Quantico, Va., home of the national DNA database.
In every state but Louisiana, arrestee DNA sampling is limited to those arrested for felonies. The Bayou State, however, also allows sampling of those arrested for some misdemeanors, including prostitution and assault.
California, Louisiana, Kansas and New Mexico and the federal government can keep DNA records even if arrestees are cleared of all charges - a practice that has brought objections from civil libertarians.
Led by the American Civil Liberties Union (ACLU), critics say the state and federal laws reverse constitutional guarantees and render suspects guilty until proven innocent.
Supporters say the aim is to develop a network of shared information to fight crime nationwide. DNA sampling of convicted felons has been used to aid thousands of investigations, according to a state-by-state clickable map maintained by the FBI.
DNA evidence has also been used to exonerate those who have been wrongly convicted. Nationwide, more than 180 people have been freed with the help of DNA evidence since 1989, according to the Innocence Project , a legal clinic based in New York.
Of those, 14 originally were sentenced to death.
In Virginia, one of the few states to release records of arrestee "hits," or DNA matches, law enforcement officials found 288 matches that have helped crime investigations since the program began in January 2003, said Paul Ferrara, director of the state's Department of Forensic Science. Fifty-nine of those were associated with sexual crimes, he said.
Although federal arrestee DNA sampling has not yet begun, enactment of the DNA Fingerprinting Act allows the five states already taking DNA samples of arrestees to begin uploading profiles into the national database.
In late June, Virginia became the first state to begin uploading profiles, sending data on about 4,000 arrestees. Louisiana followed on July 11, uploading the first 14,000 of an initial 45,000 arrestee profiles.
Civil libertarians oppose placing the burden of destroying DNA records on a defendant who has been acquitted, rather than the government. California, Louisiana, New Mexico and federal arrestees who are acquitted must request that their samples and profiles be removed from labs and databases. Usually, those acquitted must provide written notification, sometimes including a certified court order, to have the records destroyed.
Kansas is the only state that refuses to destroy all DNA records of those who have been acquitted.
Minnesota, Texas and Virginia automatically delete samples and profiles when arrestees are cleared of charges.
Joe Cook, executive director of the Louisiana ACLU, said there is "no reason" for states to keep DNA samples after acquittal. The practice turns arrestees into "a suspect every time a crime is committed," he said.
Civil libertarians want DNA samples to be treated differently from fingerprints. Cook said DNA contains sensitive personal information, including medical and racial indicators that can be used to illegally profile suspects.
"The potential for abuse is great," Cook said.
Kansas state Rep. Pat Colloton (R), who authored the bill that initiated her state's DNA sampling program, said she expects crime rates to decrease as a result of the legislation. But she also anticipates legal challenges to arrestee sampling across the country.
"I do believe this issue will go to the United States Supreme Court," Colloton said.