A federal judge has dismissed a lawsuit filed by Kansas sex offenders confined indefinitely in a state program for post-prison mental health treatment.

U.S. District Judge J. Thomas Marten ruled this week that the suit failed to provide details to support claims that the treatment the offenders are receiving at Larned State Hospital in western Kansas is so inadequate that their confinement is unconstitutional.

Kansas law allows the courts to order sex offenders held indefinitely for treatment after they’ve served their prison sentences.

The 25 men who filed the lawsuit in 2014 are among more than 250 offenders confined in the program. Only a relative few have been released since it began in 1994. The U.S. Supreme Court declared the program constitutional in 1997 because of the promised treatment.