An Indiana teenager who police say strangled his 10-year-old brother to satisfy an urge to kill that he likened to hunger pleaded guilty to murder Monday, and his defense attorney described him as remorseful.

But a prosecutor called Andrew Conley a psychopath and said the teen should stay in prison for the rest of his life.

Conley, 18, entered his plea as jury selection was to begin for his trial in the small Ohio River town of Rising Sun, Ohio Circuit Court administrator Connie Sandbrink said.

Sandbrink said Conley, who has no deal with prosecutors, faces a minimum sentence of 45 years in prison. Prosecutors have requested a sentence of life without parole. His sentencing hearing was scheduled to start Wednesday, and Sandbrink said it was expected to last three to four days.

"Bottom line, this is Andrew's decision and it's what he wanted to do," his attorney, Gary Sorge, told reporters Monday at a news conference that Cincinnati television station WLWT covered. "He's been very remorseful, and from the beginning he's wanted to plead guilty, but as defense attorneys we have our job to do, and that's what we've done."

Conley was to be tried as an adult but couldn't face the death penalty because he was 17 when his brother, Conner, was killed last November. Defense attorneys had been expected to argue Conley was insane at the time. Dearborn-Ohio County Prosecutor Aaron Negangard had described the teen as "just evil."

Negangard told the Cincinnati Enquirer on Monday that Conley was "psychopathic" and will pose a risk to other people if he's released from prison. The prosecutor told WCPO-TV that Conley's age is one of the problems with the case because he would be released "at a relatively young age" with almost any sentence given to him.

Negangard and Sorge did not immediately return phone messages to The Associated Press seeking additional comment Monday.

Police said Conley told them he had fantasized about killing people since he was in eighth grade and identified with the fictional television serial killer, Dexter. They said he told investigators that on the morning of Conner's death, he stood over his sleeping father with a knife and thought about killing him.

Conley told investigators he wrestled his brother unconscious, strangled him and put his body in a trunk, where it stayed while the teen stopped to give his girlfriend a "sweetheart ring," according to a police affidavit. He later dumped the boy's body in a park near a school, the document said.

The teen said he strangled his brother because, "I felt like I had to" and likened the urge to a hungry person satisfying a craving for a hamburger, the affidavit said.

Friends and neighbors have described the Conley family as "strong" and "balanced" and said both boys were good students who stayed out of trouble.

"(Andrew Conley) just didn't seem to have any character like that," said the Rev. Greg Matthew, the pastor of the Rising Sun Church of Christ who preached at Conner's funeral. "He wasn't in trouble with the law, he didn't make bad grades, he just seemed to be a normal teenager. He just seemed to be a quiet boy."