The twisted soul of the Wichita serial killer known as BTK likely lies beneath a calm, everyman exterior, according to Mike McKenna.

“He probably seems like a quiet person that pretty much stays to himself,” said McKenna, a former Wichita Police investigator who is now chief of the Baldwin Police Department. “He just goes and does his job every day and goes home.”

McKenna spent much of his 22-year career in Wichita tracking down tips in the BTK murder cases. He wasn’t surprised last week when the killer re-emerged into public view with a letter to the Wichita Eagle.

“I know a number of my former colleagues were surprised that he was still in Wichita,” McKenna said. “I was not. I felt all along that he lived in Wichita, stayed in Wichita.”

The name BTK stands for “bind, torture and kill.”

Six of BTK’s victims, killed between 1974 and 1979, were strangled; one was stabbed to death. Four were members of one family — two children and their parents. Letters claiming responsibility for the slayings, which remain unsolved, were sent to The Wichita Eagle and KAKE-TV. Before last week’s letter arrived, the latest had been received in 1979.

In the new letter, BTK took responsibility for an eighth murder, the 1986 strangling of Vicki Wegerle. The letter included photos of the crime scene.

McKenna, who spent the latter part of his Wichita career in charge of the special investigations section that worked on the BTK murders, said investigators never before connected Wegerle’s death to the serial killer.

“There was nothing — it was outside the pattern he had set,” McKenna said.

He said BTK contacted the Eagle after 25 years of silence out of a desire for media attention.

“He always felt slighted by the press,” McKenna said. “He felt he was as good or better than the Zodiac murderer (a still-uncaught serial killer in California). Now he’s receiving that attention.”

Investigators hope they can use new DNA technologies to perhaps identify the killer from old evidence, or from the newest letter. But McKenna said the case might be resolved only when a new witness stepped forward.

“I’ve felt for years he took photographs of his victims at the time of the killings, and he has proven that correct,” McKenna said. “I also believe he took audio recordings of the kills while they were in progress. I think that helps him recall that kill and get the enjoyment of it. He plays them the way people play their favorite CDs at home.

“I’ve hoped for years someone would find his collection … and either know it was some of the victims, or find it strange and call the police,” McKenna said.

6News video: Serial killer’s resurfacing doesn’t surprise Baldwin police chief In Wichita, edginess sets in (03-28-04) In Wichita, edginess sets in (03-27-04) Wichita revisits horror of BTK serial killings (03-27-04) Letter linked to ’70s killer (03-26-04)

McKenna worked for the Wichita Police Department between 1974 and 1996. He worked for Boeing for several years before becoming Baldwin chief last year.

He said he didn’t miss the renewed flurry of investigative activity that is happening in Wichita now.

“I very much enjoy my job in Baldwin,” McKenna said. “I’ve worked my share of murder cases in my career, after 18 years in investigations. There are people there in the police department that I’m very confident in their abilities to solve the case.”

But McKenna said he still thought about BTK.

“He’s always an individual that’s intrigued me, that I wish I could interview,” McKenna said. “I’d like to know how his mind works.”

— The Associated Press contributed to this story.