MINNEAPOLIS (AP) - A federal appeals court ruling that says Minnesota's sex offender program is constitutional is a setback for critics of the program.

That's according to Eric Janus, a professor at Mitchell Hamline School of Law in St. Paul and a leading expert on such programs.

Janus says the appellate court decided Tuesday that U.S. District Judge Donovan Frank held the state to too strict a standard in analyzing the program. The appellate justices ordered that he instead apply what's called the "rational basis" test instead - which Janus says means the state has more leeway in the program's design.

But Janus says Frank might still find the program unconstitutional under the looser standard. He says the ruling is not a "death knell" for opponents who criticize the program because releases are so rare.