A disclosure statement and an extensive interview with RCMP investigators in 2009 were supposed to canvass every illegal act a lifelong criminal who would become a police agent had ever committed.

But it wasn’t until 10 days before the murder conspiracy trial of three Cranbrook men began last month that key Crown witness Garry Shank reported to police and a Crown prosecutor that he’d committed a murder.

Lonnie Adams, Kevin Correia and Lorne Carry are on trial for conspiring to kill a drug rival in the East Kootenay town. Shank testified earlier this month to signing on to become a police agent in the investigation, including wearing a recording device as he plotted with the three men.

On Tuesday, the head of the RCMP’s combined forces special enforcement unit in Kelowna, Staff Sgt. Cary Skrine, testified during cross-examination about the process of signing on Shank to become an agent.

Shank testified earlier in the trial he wanted to change his life and agreed to work with police. He’s a lifelong criminal who never held a job.

Unlike an informant or confidential source, police agents sign a contract agreeing to perform in scenarios directed by RCMP. Skrine said the process of signing on a police agent is an onerous one, involving detailed interviews and extensive police investigation to determine whether statements given in the interviews are true.

But Shank was never put through a police polygraph test before he became a police agent late in 2009, despite the insistence of one senior member.

Defence lawyer Jim Heller sent a memo to Skrine from another Mountie that said hiring Shank as a police agent couldn’t be done without a polygraph.

Skrine said he hadn’t seen that document.

Another defence lawyer, Don Campbell, said Shank told police in the interview and disclosure late in 2009 that he’d never committed a murder.

“You’re aware he was adamant he didn’t commit a murder?” asked defence lawyer Don Campbell. “He said, ‘Go ahead and put me on a polygraph.’”

The senior Mountie agreed that Shank lied during his disclosure interviews with police, saying he’d never killed anyone.

“We didn’t detect a lie until he told us about it (before the trial),” Skrine said.

Because potential agents aren’t given their Charter rights, the admissions can’t be used in court. There is also an unwritten agreement that police will not use the incriminating statements to open an investigation and obtain other evidence.

But immunity is not granted, Skrine said.

Heller asked Skrine if police would have signed Shank on as an agent if he had disclosed the murder at the outset.

“Possibly it would have been a dilemma,” Skrine said.

No information about that killing was presented in court.

“I’m not 100 per cent sure how that would be handled,” he said. “If there was a police investigation, I’d want to pass it on, but it’s not in the spirit of the interview.”

The jury trial began in February and is slated to complete at the end of April.