EDMOND, Okla. (AP) -- A man police arrested on felony peeping tom charges may be the killer investigators here have been trying to find for 18 years, authorities say.

Oklahoma County prosecutors charged Jonathan Scott Graham, 38, on Friday with first-degree murder in the 1986 killing of Gary Dale Larson.

Graham was in custody on 15 counts of possession of child pornography and two counts of taking clandestine photographs when investigators found evidence connecting him to the unsolved killing.

Edmond Police Chief Bob Ricks said detectives still remembered the unsolved slaying of Larson, 27, and the rape of his fiancee.

Detective Scott Day, the first one on the scene of the crime on the morning of Aug. 16, 1986, said he saw Larson's fiancee standing in the doorway, hand over her mouth, blood on her body.

"She said, 'He's dead. I know he's dead. Is he dead?"' Day said.

Larson was stabbed 24 times in the chest and stomach.

The woman told police that Larson went to check out a suspicious noise around his residence but never came back. When she went to investigate, she saw a man, who captured her, tied her up and assaulted her repeatedly at knifepoint, police said.

She was left in a closet, but escaped and called police. The killer left behind a footprint.

He recalled the crime April 5, when he went to investigate a report of a peeping tom at Scott Eagleston's residence.

"I saw the overgrown bushes, and I got an eerie feeling," he said, standing less than a block away from the 1986 crime scene.

Eagleston told police he went outside when his motion detector went off and found Graham lying barefoot on the ground.

Police reports state that Eagleston yelled at Graham, and then chased, tackled and subdued him after Graham tried to walk away, police said.

Investigators found that Graham had been charged in Waco, Texas, with unlawfully carrying a weapon. He was caught in June 2000 with a "sex bag" that was filled with black clothing, gloves, duct tape, sex toys, knives and other items, Ricks said.

The department sent copies of the bloody footprint left in Larson's house and one taken from Graham on his recent arrest. Investigators determined Wednesday the prints matched.

The OSBI is working to compare DNA samples from Graham and semen from the rape. The statute of limitations has expired for any rape charges.