Prince William County sued the federal government Thursday over its illegal immigration policy. It was the second lawsuit in six months.
County officials want to know the whereabouts of 4,000 illegal immigrants transferred to the custody of Homeland Security over the past four years.
In 2007, Prince William began checking every person arrested for their immigration status. Those who were found to be in the U.S. illegally were turned over to Homeland Security.
Prince William officials believe the federal government simply released many of the illegal immigrants instead of deporting them.
About 400 of the illegal immigrants transferred to Homeland Security have been re-arrested by Prince William police, according to county officials.
Six months ago, Prince William County sued the federal government over the release of an illegal immigrant who is accused of killing a nun in a car accident.