Wichita ? The woman who was married to serial killer Dennis Rader for more than 30 years once found a draft of a poem he wrote about one of his victims, but Rader said in his confession to authorities that he convinced her the piece was for a college class assignment.

The poem, “Shirley Locks” – based on a child’s “Curly Locks” rhyme – later was mailed to The Wichita Eagle-Beacon after the 1977 murder of Shirley Vian Relford. She was the sixth victim of the BTK killer – Rader’s self-coined nickname that stood for “Bind, Torture, Kill.”

Rader, 60, began serving 10 consecutive life sentences on Friday.

Paula Rader, who divorced her husband shortly after he pleaded guilty to killing 10 people in and around Wichita from 1974 to 1991, has remained in seclusion since his arrest in February. The revelation that Rader kept sexually deviant materials and trophies from his kills around the couple’s home in suburban Park City led to speculation that she might have turned a blind eye to his activities.

“She told us she didn’t know,” Police Chief Norman Williams said Friday. “We have to believe her word on that.”

Not everyone does. A thread titled “I’m Not Buyin’ Paula’s Story” had drawn more than 180 posts by late Friday on The Wichita Eagle’s BTK message board, although some of the messages supported her.

But authorities have said they do not believe Paula Rader knew her husband was a killer, and a court document filed by prosecutors on Thursday appears to bolster that.

According to the document, Rader, who was attending Wichita State University at the time of Relford’s murder, told investigators he accidentally left the draft of the “Shirley Locks” poem on a chair.

“It scared, scared her,” Rader tells his interrogators in the document. “She said, ‘Well, what’s these?’ I said, ‘Well, we are working drafts because we are doing this BTK thing, whatever, you know, at school.'”

Rader, a father of two grown children, holds a degree in administration of justice from Wichita State.

The newspaper did not immediately recognize the poem as a BTK communication, mistakenly forwarding it to the classified advertising department.

Paula Rader also made a reference to the similarity between her husband’s poor spelling and the misspellings in BTK’s letters, Dennis Rader said in the court document: “In fact, my wife said to me the other day, she said, ‘You spell just like BTK.”‘

But Paula Rader did not pry into her husband’s things, police said, including the plastic storage box he kept in a closet that contained some of the trappings of his secret life.

Paula Rader “didn’t really go in that closet,” Williams said. “She really didn’t question him.”