US law enforcement currently catalogs 5.6 million DNA profiles, about 2% of Americans, but hopes to expand that and the scope of their searches, the Wall Street Journal reports. A bigger database would allow "familial searches"—looking for near matches of a suspect's brother or sister, for example. Civil libertarians worry the practice will expose innocent people to government scrutiny.
Most of the database consists of convicted felons, but 11 states now allow DNA to be collected from anyone arrested, even for minor offenses, and the Department of Justice will soon follow suit. The US is following the lead of Britain, which has nearly 8% of its population databased and uses familial searches. One US study warns it would put innocent people “under lifetime genetic surveillance.” (Read more DNA database stories.)