A homeless man has admitted that he stole a wedding ring off the finger of a man who was stabbed to death in May on a Portland light-rail train. Authorities say the suspect in the killing also killed another man and wounded a third.

The homeless man, George Elwood Tschaggeny, 51, pleaded guilty Monday to theft, identity theft and tampering with physical evidence, court records said.

His plea petition involving the theft from stabbing victim Ricky Best indicated Tschaggeny is expected to receive a punishment of 13 months in prison at his sentencing on Nov. 14.

"I unlawfully and knowingly stole personal property from Ricky Best during a catastrophe," Tschaggeny wrote in the plea agreement.

Tschaggeny was wearing Best's ring when officers arrested him about a week after the stabbings that stunned Oregon's largest city. Investigators said he also stole Best's wallet and used his credit card five times. Tschaggeny said in court papers that he charged items at grocery and sporting goods stores.

Best was one of three passengers stabbed on May 26 during a confrontation that started when a rider yelled at two black girls, one of whom was wearing an Islamic head covering called a hijab.

Best died on the train, and another victim died at a hospital. The other man survived.

Amid the mayhem on the train, authorities said, Tschaggeny removed the ring from Best's finger and stole his backpack. Police said the theft was caught on surveillance video.

Tschaggeny in 2010 was awarded a civilian medal by Portland police after he helped stop an armed bank robber.

At some point after that he got addicted to painkillers and ended up homeless, his relatives told KOIN-TV and The Oregonian/OregonLive.

The man charged in the stabbings, Jeremy Christian, has pleaded not guilty to aggravated murder and other crimes. He's being held in a Portland jail without bail.