After BTK murdered four members of the Otero family in 1974, William A. Cornwell spent three days and nights at police headquarters, sleeping fitfully in a chair, sending out for sandwiches, running down every lead. He'd walked through the Otero house, seen the two children, the four bodies.
"Nobody went home until we could run out every lead we had," he said Saturday.
They got nowhere.
Cornwell, now 75, was chief of detectives when the Oteros died, and when Kathy Bright was stabbed, and when BTK strangled Nancy Fox three years later. No one could be happier that there are an arrest, a pending trial and a witness list.
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He is one of the nearly 250 people listed as potential witnesses in the Dennis Rader case, and he doesn't mind at all. When he retired in 1980, he left frustrated.
"We hadn't caught the guy, and hadn't stopped him from hurting other people," he said.
He and the other detectives ran down every lead they got and tried everything they could think of to find the killer. The pressure was high. The press and the public demanded to know why they failed to catch someone.
"It was just so frustrating," he said. "We worked it hard. I told people: 'Talk to every possible person, every paperboy in the neighborhood, every milk man, anybody.' "
Cornwell knew, from years of detective work, that most criminals can't resist telling someone what they'd done. The detectives set out to find that someone.
But it became clear that BTK came out of a different mold.
"He was lucky," Cornwell said. "Not smart, but lucky, and he was a loner; he didn't talk to anybody. Most criminals do talk to other people — and if you find that somebody, then you're in."
Cornwell, who retired in 1980, was traveling on a bus in February when his cell phone rang and someone told him that Rader had been arrested.
He felt satisfaction and a great deal of relief. He also felt a desire, after all these years, to do one more interrogation.
"There are so many questions you have after you work a case like those."
Given the chance to interview BTK, Cornwell said: "I'd love to ask him how he got into the Otero house. And of course I'd like to ask him why he was doing this. His letters explain some of it, that he had a monster in his brain, or whatever it was that he said."
That explanation is probably so much smoke, he said.
"Some people are just plain mean, and that's all there is to it."