Civil commitment gained support in the 1990s amid reports of heinous sex crimes by repeat offenders. Today, 20 states, along with the federal government, detain some sex criminals for treatment beyond their prison time. But not all have been as sharply criticized as Minnesota’s program. In Wisconsin, 118 offenders have been fully discharged from commitment since 1994, and about 135 people have been given supervised release, according to Judge Frank. New York had sent home 30 people and moved 64 people out of secure facilities for the civilly committed and into strict supervision and treatment, Judge Frank wrote.

But the picture in Minnesota looks far different. Since the current program was created in the mid-1990s, civil commitments have soared. The abduction, rape and murder in 2003 of Dru Sjodin, a North Dakota college student, by a sex offender who had been released six months earlier enraged residents and set off a wave of efforts by county attorneys to call on judges to hold such offenders after prison.

Minnesota now has the highest population of civilly committed offenders per capita — nearly all men — in the nation, Judge Frank found, and the lowest rate of release. And costs have soared — to about $125,000 per resident per year, at least three times the cost of an ordinary prison inmate in Minnesota, the judge said.