A Wisconsin appeals court ruled Thursday that a man who killed a Catholic priest and two others in a church 23 years ago should be released from a mental hospital.

Bryan Stanley had claimed to be a prophet sent to cleanse St. Patrick's Catholic Church in Onalaska when he gunned down parish priest John Rossiter, lay minister Ferdinand Roth Sr. and church custodian William Hammes in 1985. He was angry the priest was allowing girls to give Scripture readings during Mass.

Stanley, who suffered from psychosis, was found not guilty by reason of mental disease and was committed indefinitely to Mendota, a state psychiatric hospital in Madison.

The District 4 Court of Appeals said state lawyers failed to prove that releasing Stanley, 53, would present a danger to himself or the public. The decision overturns a ruling by a La Crosse County judge who had denied Stanley's request for release.

Ferdinand Roth Jr., a retired police supervisor in La Crosse, Wis. and son of one of the victims, blasted the decision. He recalled that Stanley testified at a hearing last year there was not a 100 percent guarantee he would always take his medicine.

"My personal reaction is, I'm rather bitter and upset," he said. "And as a person who lives in this area, I certainly wouldn't want a person on the street who has killed three people. The system is very disappointing at times."

Department of Justice spokesman Bill Cosh said the state was considering whether to appeal to the Wisconsin Supreme Court. If it doesn't, the state Department of Health Services will be required to present a plan to a judge for the conditions attached to Stanley's release.

If Stanley is released, it likely would be under conditions including a monitoring bracelet on his ankle and staff supervision of his medicine intake. That protocol would protect the community, and Stanley would be taken back into custody if he posed a risk, state officials say.

Attorney Tom Hayes, who represented Stanley during his appeal, called on authorities to quickly approve a plan and release his client. Stanley is ready to follow any conditions imposed by the court, said Hayes, who wasn't sure where Stanley would want to live.

"He's exhibited an ability to be a pro-social member of any community over the last 15 years," Hayes said.

In recent years, Stanley has been given greater freedom as his schizophrenia has been managed with medication. He was moved to an unlocked, minimum security unit at Mendota in 2006 and has been allowed to work part-time in the community and take classes at a technical college.

He also has spent years researching and writing a 280-page book, "The Becoming of Driftless Rivers National Park," a cultural and natural history of southwestern Wisconsin.

"He's a very talented person," Hayes said. "And now with the proper medication that stabilized his condition, he was able to develop that talent."

Two doctors — one who treated Stanley at Mendota and another appointed by the court to examine him — supported his petition for conditional release.

The lower-court judge who ruled against releasing Stanley said he had refused to take his medication. The appeals court, however, said he refused for one day in 1993 because of side effects, and that since switching his medication 15 years ago he has never refused.