GRESHAM, Ore. – Police arrested a Portland man who they said sexually assaulted a woman on the Springwater Corridor bike trail on March 18.

Investigators identified Thomas Peacock, 50, as the suspect after following up on several tips, according to Detective Fred Huffman. Police said that Peacock was homeless.

Peacock spent 31 years in prison, from 1984 to 2015, but he escaped for one day on May 1, 1988. On that day, according to Betty Bernt with the Oregon Department of Corrections, Peacock committed attempted aggravated murder and robbery before he was caught on May 2. He was sentenced in December to 30 years in prison.

Police in a news release said Peacock had an outstanding arrest warrant from the Oregon State Parole Board for "the underlying charge of homicide."

Investigators received a tip that Peacock was in Southeast Portland, near Oaks Park, Thursday afternoon. The East Metro SWAT team and Gresham detectives found Peacock near the entrance of Oaks Bottom Wildlife Refuge and took him into custody.

Peacock was booked into the Multnomah County Jail on charges including rape, kidnapping, unlawful sexual penetration and robbery in the first degree.

An ‘Affidavit of Probable Cause’ obtained Friday, detail the case against Peacock. Investigators say the victim, a 22-year-old woman, flagged a man, now believed to be Peacock, down for help on the Springwater Trail.

The woman told officers he “started to hand her a bicycle pump, but then quickly grabbed her forearm with one hand and used his other hand to grab a knife that was clipped to [the victim’s] front pants pocket. He then held the knife to her throat and told her he would kill her if she screamed or tried to get away.”

The documents say “the suspect then forced her to walk down a trail to a secluded area, made her get on the ground…” where the victim says he raped her.

According to the affidavit, at some point during the assault Peacock “asked [the victim] if she was a virgin.”

She “responded that she was and that she was only twelve years old.”

The victim said “this appeared to alarm the defendant and he quickly got dressed and left the scene.”

The affidavit also details the tip that led police to Peacock. Investigators say it came from his brother Melvin.

Investigators write that Melvin Peacock called investigators and “said he had information pertaining to the investigation.”

He told a detective “he lives in a house near the Springwater trail with his wife…and that they had seen the defendant shortly after the rape occurred. Peacock explained that the defendant is his brother, and that he matched the description he saw on the news of the suspect.”

Melvin Peacock told investigators “on the date of the incident, his brother rode a bicycle on the Springwater trail on his way to Peacock’s home… and that the defendant had arrived a very short time after the reported incident."

He added "the defendant’s pants were muddy and that he was wearing a red jacket when he arrived at the house… the defendant showed up with two knives, which was odd because he usually carried one knife...”