Topeka ? A federal judge has dismissed a lawsuit brought by Kansas sex offenders who are confined indefinitely in a state program for post-prison mental health treatment, saying they didn’t do enough to substantiate their claims.

U.S. District Judge J. Thomas Marten ruled Monday that the lawsuit failed to adequately argue that the treatment the offenders are receiving at Larned State Hospital in western Kansas is so lacking that their confinement violates their constitutional rights.

Kansas law allows the courts to order sex offenders to be held indefinitely for treatment after they’ve served their prison sentences. Legislators created the program in 1994 after the rape and murder of a college student by a sex offender who had been released from prison, and the U.S. Supreme Court declared it constitutional in 1997 because of the promised treatment.

The 25 men who filed the lawsuit in 2014 are among 261 offenders now being held in the Sexual Predator Treatment Program. Four offenders have been released since the program’s inception and nine others are living independently but are still under court supervision, according to the state Department for Aging and Disability Services.

The plaintiffs argued that because the services provided to them were inadequate, they couldn’t finish treatment and earn their release. The state sought to have the lawsuit dismissed, and Marten said the offenders didn’t document the details of their treatment and how it failed to meet accepted standards.

“Merely labeling the conditions as punitive or unwarranted, without accompanying allegations showing a plausible factual basis for such a finding, is insufficient to withstand a motion to dismiss,” Marten wrote in his ruling.

Donald Peterson, a Wichita attorney representing the offenders, didn’t immediately reply to a Wednesday phone message seeking comment.

Attorney General Derek Schmidt said in a statement that the program “makes important contributions to public safety” and, “the court’s decision leaves the program intact.”