WICHITA, Kan. - For nearly an hour, the balding figure in a tie and jacket matter-of-factly told a tale of horror that shocked the community he had terrorized for three decades.

He chillingly recounted how he trolled the neighborhoods of Wichita randomly stalking his prey. He talked about how he hung an 11-year-old girl from a sewer pipe after murdering her parents and brother. He described strangling a 62-year-old woman with pantyhose and dumping her body under a bridge.

Dennis Rader provided the grisly account Monday as he confessed to being the BTK serial killer and pleaded guilty to 10 murders, saying he shot, stabbed or strangled his victims to satisfy his sexual fantasies.

Rader, a 60-year-old former code inspector and church president with a wife and two children, will almost certainly go to prison for the rest of his life when he is sentenced in August.

In pleading guilty, an unfailingly courteous and emotionless Rader helpfully corrected the judge on some matters, clarified others, and at one point launched into an almost scholarly discourse on the mind and habits of a serial killer.

"If you've read much about serial killers, they go through what they call different phases. In the trolling stage, basically, you're looking for a victim at that time," he said. "You can be trolling for months or years, but once you lock in on a certain person, you become a stalker."

Rader also described how he used a "hit kit" consisting of guns, rope, handcuffs and tape in a briefcase or a bowling bag. He talked of his first four victims almost as animals, saying he decided to "put them down." And he said he offered one victim a glass of water to calm her down before putting a bag over her head and strangling her.

Those who watched or listened to him in court on Monday were struck by how utterly ordinary he looked - dressed in his tie and jacket, with a neatly trimmed goatee and gold wire-rimmed glasses - and by the air of detachment with which he recounted his crimes.

"He was so cold about it," said 19-year-old Jared Noble of Wichita, who listened on the radio. "The way he described the details - heartless - with no emotion at all."

The man who called himself BTK - for his preferred method, "Bind, Torture, Kill" - cannot get the death penalty because the killings occurred before Kansas adopted capital punishment. But each count carries up to life in prison. The guilty pleas came on the day that his trial was supposed to start. Sentencing is Aug. 17.

For the families of Rader's victims, the confession answered questions that had haunted them for decades.

Most of the victims' relatives in court stared silently, though one wiped away tears during Rader's nearly one hour in front of the judge. After the hearing, they were asked by prosecutors to avoid reporters.

"Today in court, for the first time, our community and the nation have now heard Dennis Rader reveal that he has committed those homicides," District Attorney Nola Foulston said. "Today we have some resolution."

The BTK killer taunted media and police with cryptic messages during a cat-and-mouse game that began after the first murder, in 1974. BTK resurfaced in 2004 after years of silence with a letter to the Wichita Eagle that included photos of a 1986 strangling victim and a photocopy of her missing driver's license.

That letter was followed by several other cryptic messages and packages. The break in the case came earlier this year after a computer diskette the killer had sent was traced to Rader's Lutheran church, where he once served as president.

When questioned by the judge about the motivation for the first four slayings, Rader said: "That was part of what you call my fantasy."

Pressed further, Rader said, "Sexual fantasy, sir."

Rader has not been charged with sexually assaulting his victims, but he admitted masturbating over some of them.

He did not reach a plea bargain with prosecutors. Defense attorney Steve Osburn said the evidence against Rader included a confession, DNA and "personal trophies" taken from his victims. Rader said those included a watch, a radio and a necklace.

For his own part, Rader said he pleaded guilty because a trial would be "just a long process. So it's just a mathematical problem. It's guilty."

Unlike the stereotype of the serial killer as a loser and a misfit, Rader lived a remarkably stable life. He has been married for 34 years and worked in suburban Park City as a code inspector, handling stray dogs and looking for violations such as overgrown grass.