Should already vast DNA database expand?

The DNA of more than 3 million people already exist in databases across the nation, and state and local government are rapidly expanding the rules for whose DNA can be catalogued, the Washington Post reports.

"This is the single best way to catch bad guys and keep them off the street," said Chris Asplen, a lawyer with the Washington firm Smith Alling Lane and former executive director of the National Commission on the Future of DNA Evidence. "When it's applied to everybody, it is fair, and frankly you wouldn't even know it was going on."

But what about privacy concerns? Is the tradition that law-abiding citizens are not gathered up in law enforcement data collections in danger of being made irrelevant?

"These databases are starting to look more like a surveillance tool than a tool for criminal investigation," said Tania Simoncelli of the American Civil Liberties Union in New York.

Once someone's DNA code is in the federal database, critics say, that person is effectively treated as a suspect every time a match with a crime-scene specimen is sought -- even though there is no reason to believe that the person committed the crime.

There are several serious privacy issues around DNA collection.

• Police have run "DNA dragnets," where thousands of people were asked to submit blood or tissue samples to prove their innocence.
• Familial searching targets family members of known criminals when DNA similar but not identical to that of criminals is found.

  Law enforcement officials say they have no interest in reading people's genetic secrets. The U.S. profiling system focuses on just 13 small regions of the DNA molecule -- regions that do not code for any known biological or behavioral traits but vary enough to give everyone who is not an identical twin a unique 52-digit number.

  "It's like a Social Security number, but not assigned by the government," said Michael Smith, a University of Wisconsin law professor who favors a national database of every American's genetic ID with certain restrictions.

  DNA is a very powerful tool for crime fighters. Consider the case of a Canadian woman sexually assaulted in Mexico.

  Canadian authorities performed a semen DNA profile and, after finding no domestic matches, consulted the FBI database. The pattern matched that of a California man on probation, who was promptly found in the Mexican town where the woman had been staying and was charged by local authorities.

  Still, is law enforecement going too far? The Post explains: "At least 38 states now have laws to collect DNA from people found guilty of misdemeanors, in some cases for such crimes as shoplifting and fortunetelling. At least 28 now collect from juvenile offenders, too. The federal government and five states, including Virginia, go further, allowing DNA scans of people arrested. At least four other states plan to do so this year, and California will start in 2009."