DEER LODGE, Mont. (AP) -- Barry Beach testified at his own clemency hearing Friday, adamantly denying any part in the 1979 killing of a Poplar girl that landed him a 100-year prison sentence.

"I did not kill Kim Nees," Beach, 45, told the Montana Board of Pardons and Parole.

For nearly two hours, Beach talked about the days and months surrounding the killing.

Beach said interrogators yelled at him and accused him of other murders before the confession he now says he does not recall giving.

The executive clemency hearing, a rare occurrence, reached its final day with the convicted murderer's advocates wrapping up their case with Beach on the stand.

The board gave both sides one week to submit closing arguments, with a clemency decision possible in the next month. The board will reconvene Aug. 1 to open the second part of the hearing, dealing with a possible commutation that could lead to parole.

Beach's lawyers called witnesses in the past few days who blamed a group of girls for the murder. Beach's sister also spoke, saying she saw Beach sleeping at home the night of the murder -- the first time an alibi has been offered.

Prosecutors have held up a 14-page transcript of the original confession backed up by testimony from former Gov. Marc Racicot, the original prosecutor, who said the case was one of the most convincing he has seen.

But Beach, arrested in Louisiana in 1983 for a domestic dispute, said investigators there threatened to pin local murders on him if he did not fess up. He said they alternated between yelling at him, being nice or praying with him.

A detective threatened to send him to the electric chair and said, "he couldn't wait to be the one that pushes the button and sees that happen to me," Beach said.

Finally, Beach said, he "broke weak."

Those same detectives testified earlier in the three-day hearing that they never threatened Beach.

"I do not remember giving this so-called confession," Beach said. "I don't remember any point in time that the machine was turned back on and I gave this confession."

Beach said he cooperated during the all-day session to clear his name. The U.S. Navy released him from the military after his arrest, but said he could return when he was no longer a suspect in the Nees murder.

In the lengthy confession from 1983, Beach describes forcefully trying to kiss Nees and getting angry at her for fighting back. In the transcripts Beach described hitting her with a wrench and a tire iron, and then thinking, "Oh my God, what have I done?" after checking Nees's pulse and finding she was dead.

Assistant Attorney General Mike Wellenstein said Beach conveniently remembers intimate details of his talks with detectives -- up until the time he gave the actual confession.

Parole board member Vance Curtiss said the board will have a difficult task sorting through hours of testimony from many sources.

"I have not made up my mind at this point in time," he told Beach. "Whatever comes out of this hearing, we want you to understand we have taken a lot of information.

"We are trying to filter this all out."

In the end, the board will have to either believe Beach's claim that the confession is false -- against testimony from the original detectives who said it is ironclad. Or they will have to believe testimony from witnesses who said they have heard two women talk about being involved in the killing.

The attorney general's office has questioned why Beach waited until now, through several courtroom appeals, to bring forward new information such as the alibi.

Former Roosevelt County Sheriff John Grainger said he does not buy the theory that Nees was killed in a gang attack by teenage girls.

"At some point somebody is going to say something," he said. "A conspiracy like that just doesn't hold together."

Beach lawyer Peter Camiel challenged the assertion, pointing to witnesses in the first two days of the hearing who overheard confessions from at least two of the women.

"It just seems odd to me that after all this time, these things are coming forward," said Grainger, now administrator of the Department of Livestock's Brands Enforcement Division.