Six years ago, the federal government set out to indefinitely detain some of the nation's most dangerous sex offenders, keeping them locked up even after their prison sentences had ended.
But despite years of effort, the government has so far won court approval for detaining just 15 men.
Far more often, men the U.S.Justice Department branded as "sexually dangerous" predators, remained imprisoned here for years without a mandatory court hearing before the government was forced to let them go, a USA TODAY investigation has found. The Justice Department has either lost or dropped its cases against 61 of the 136 men it sought to detain. Some were imprisoned for more than four years without a trial before they were freed.