A former Gladstone police sergeant admitted to arranging his wife's murder but regretted putting his trust in "drug addicts" to carry it out, a Multnomah County jail inmate testified Tuesday.

Travis Layman said he became friends with Lynn Edward Benton while they were in protective custody at the Multnomah County Detention Center for at least three months in 2015. They talked about their cases while working side by side delivering food to other inmates and performing janitorial duties, as well as during their recreation time, he said.

Over time, the inmate said, Benton explained that he wanted Debbie Higbee Benton dead, how his friend Susan Campbell failed to fatally shoot his wife in the wife's beauty salon in May 2011, and how Campbell's son Jason Jaynes finished the killing as Benton watched.

"He said he was glad he had Jason there because he wouldn't have had the cojones to do it." said Layman, 42. "He didn't have the nerve. Otherwise he said he would have done it himself in the first place."

Layman was the only person who testified in front of the jury Tuesday during Benton's trial in Clackamas County Circuit Court. Opening statements began Sept. 14. Benton, 54, is accused of offering $2,000 to Campbell and Jaynes to kill Higbee Benton and has been charged with aggravated murder, solicitation to commit aggravated murder, criminal conspiracy to commit aggravated murder and attempted murder. He also is accused of at least one prior attempt to kill his wife.

A conviction for aggravated murder could put Benton on death row. A trial for Jason Jaynes is scheduled for March 2017. No date has been set for Campbell's trial.

Benton, who spent the majority of his near 25-year police career as a woman, married Higbee Benton in 2010. That same year, he began transitioning to male, which prosecutors said caused a rift between the couple. Benton had moved out of their Gladstone home a month before his wife's death.

Layman has several gun, drug, forgery and burglary convictions dating back to 1993. He testified that he spent nearly 13 years in prison in Washington after being found guilty of robbery and gun possession in 2001. He is being held in a Multnomah County jail on accusations stemming from an armed robbery in Portland in September 2013, four months after he was released from prison.

Layman is the prosecution's key witness and provided information about Benton during at least three interviews with investigators in exchange for lighter sentences in Multnomah County and Clackamas County. For the former, his agreement calls for him to serve at least 5 years and 10 months in prison for first-degree burglary, second-degree kidnapping, second-degree robbery, attempted aggravated theft and unauthorized use of a motor vehicle. He already has pleaded guilty to those charges, as well as to unlawful delivery of methamphetamine stemming from the Clackamas County case.

He is scheduled to be sentenced in both cases after Benton's trial.

Clackamas County Senior Deputy District Attorney John Wentworth said Tuesday that a representative from his agency will appear during Layman's sentencing in Multnomah County to tell the judge he aided with the murder case as part of Layman's cooperation agreement. Wentworth said the deal doesn't call for Clackamas County making a sentence recommendation, won't stop Multnomah County prosecutors from recommending a higher sentence and won't prevent the judge from possibly imposing a sentence longer than the nearly six-year minimum. The sentence in the Clackamas County case would be lesser and be served at the same time.

Layman testified that he and Benton at some point had neighboring cells at the Multnomah County jail. They were let out six to eight hours a day and spent most of that time together, he said. When in their cells, they communicated through an air vent near their toilets.

Layman said he initially didn't know why Benton was in custody and that he and other inmates suspected Benton was facing accusations of child sex abuse. Layman said his impression changed after getting to know Benton. Although he didn't know what Benton was accused of at first, Layman said he believed the former cop's initial claim that he was framed.

"There's a lot of people in jail who say they're not guilty, for a while," Layman said. "I didn't look at [Benton] and thought he was a killer... I thought maybe this is the only guy I've ever met in jail who's innocent."

During cross examining, he admitted that it was through a jail deputy that he learned that Benton was accused of aggravated murder. Benton at first told Layman he was a Greyhound bus driver, but later admitted that he was a former police officer.

While testifying, Layman said that Benton first confessed to him when Layman was lamenting to the former cop that he wished his latest crime, the Clackamas County case, occurred in Multnomah County because they tended to be "more lenient" in prosecution. Benton said he wished he had also, Layman said.

Benton claimed he should have stopped after an attempt to get his wife to overdose on prescription fentanyl patches because "it got messy," Layman said. He said Benton never specified what that meant, but mentioned that Campbell and Jaynes were involved in that attempt.

According to Layman, Benton said he got Campbell a job working with Higbee Benton at her beauty salon, enlisted the friend to kill his wife because Campbell had talked about murder before and thought "she was good to do this one."

But Benton said Campbell and her husband were "drug addicts and unreliable," and that Campbell was the "sole reason" he was in trouble, Layman testified. Benton said the plan was for Campbell to shoot Higbee Benton when they were alone in the salon and that Campbell was supposed to steal money from the cash register to make it look like a robbery. It was supposed to happen toward the weekend when there would likely be the most money in the cash register, he said.

But Campbell panicked and called Benton at work after shooting Higbee Benton with the only bullet in the gun and she didn't die, Layman said. Benton claimed he hung up on Campbell, that he and Jaynes went to the salon to kill his wife. Benton said he then went back to patrol duty, Jaynes went back to work at a nearby gas station and they left his wife in the salon.

Benton said no one saw him or Jaynes enter or leave the salon, Layman said.

Layman said Benton claimed he "fell to the ground and won an Oscar," when he found his wife dead in her salon. Benton later claimed his defense for the jury would have been that Campbell sold her husband's drugs while he was incarcerated, that he was released around the time of the murder and that Campbell robbed the salon to replace the drugs she sold to prevent being abused by her husband, Layman said.

Benton claimed he had been a police officer for about 25 years and "knew he had retirement money coming," and didn't want to jeopardize it by getting a divorce, Layman said.

Benton also told Layman that he was concerned about a $900,000 wrongful death lawsuit filed in May 2014 by Higbee Benton's mother against him and that his spouse's family would be going after money he still had in the bank. He talked about taking that money and using it on improvements to his new girlfriend's home, Layman said. The lawsuit proceedings are on hold until Benton's trial has concluded.

Layman testified that sometime after Benton told him he wished he didn't commit his crime in Clackamas County, Layman mentioned the admission to his attorney, who contacted Clackamas County prosecutors in early June 2015 and he began talking to them about the case soon after.

He said had taken notes by the time he was interviewed the second and third time on the advice of his attorney to make sure he could accurately report what Benton was telling him.

During cross examination, defense attorney Patrick Sweeney questioned Layman's motivation for cooperating with investigators. He noted that Layman has a history of reaching out to prosecutors to offer information about other inmates in exchange for a lesser sentence. In some cases, that cooperation has included testifying against other inmates. Sweeney said. He suggested Layman was motivated to be released as soon as possible to help raise his toddler son.

Sweeney said it was clear from records that investigators and prosecutors gave Layman clues on what information to ask Benton after their first interview, when Layman couldn't answer some of their questions, such as what Benton's employment used to be.

Layman testified that he did cooperate for consideration of lesser sentences, but also in at least one case, to prevent another inmate from being harmed.

-- Everton Bailey Jr.

ebailey@oregonian.com

503-221-8343; @EvertonBailey