The grow-op in James Roszko's Quonset on his Mayerthorpe-area farm. The RCMP photo was released Thursday during the fatality inquiry. (RCMP)A member of the RCMP "green team" that responded to the grow-op on James Roszko's farm near Mayerthorpe, Alta., was told to be aware that Roszko hadn't been apprehended and might return.

The officer, Cpl. Lorne Adamitz, testified in Stony Plain Thursday at the fatality inquiry looking into Roszko’s ambush and murder of RCMP constables Anthony Gordon, Leo Johnston, Brock Myrol and Peter Schiemann on his property on March 3, 2005.

Adamitz arrived at the farm with other team members at about 12:30 a.m. March 3. He was given a quick assessment of situation by Cpl. James Martin and was told to be on the lookout for Roszko, he told the inquiry.

"He's a little bit of a wingnut, He's unpredictable. Just keep your head up," Adamitz said he was told.

Adamitz said the term "wingnut" didn’t ring any alarm bells, because it was common description used by police.

'Strong police presence'

He told the hearing the farm had a "strong police presence."

Officers found marijuana-growing operations in a bedroom and in the Quonset. Adamitz described them as "highly sophisticated soil grows." He said soil-grows are considered the bottom tier of grow-ops.

Police investigate the Quonset where the four Mounties died on March 2005. Officers who were at the scene prior to the shooting testified Thursday at the fatality inquiry. (CBC)While he didn't see any weapons in his search, he saw an unattached night vision scope.

After RCMP called the power company out to the farm to help dismantle the grow-op, they left at 2:40 a.m.

Two officers were left behind to secure the scene so the auto-theft unit could come in the morning, he said.

"I do recall Brock Myrol, and they had called a member from Whitecourt to facilitate that purpose."

When asked if efforts were made to find Roszko, he responded, "I was aware that prior to our arrival, efforts had been made."

Grace Johnston, mother of Const. Leo Johnston, asked Adamitz if he thought it was possible Roszko slipped back in the Quonset between 1 and 3 a.m.

"Could he have slipped into the Quonset? Absolutely not," he replied.

The Quonset was a hub of activity, he said.

Exchange of gunfire

Later in the day, the inquiry heard from a member of the auto-theft unit who arrived at the scene later in the morning.

Cpl. Garrett Hoogestraat speaks to media after testifying Thursday afternoon. Const. Garrett Hoogestraat was outside the Quonset when he heard an exchange of gunfire.

After running to his vehicle to call 911, he yelled at the building, asking the suspect to surrender so the downed officers could get medical attention.

He said he heard no response.

When asked what he could see, Hoogestraat's voice cracked and he paused. He was asked if he needed a moment.

He declined before responding: "You could see a member's legs at the entranceway to the door."

There was no movement, Hoogestraat said.

The inquiry is scheduled to run at the Stony Plain courthouse until Feb. 1. Public hearings held under the Alberta Fatality Inquiries Act are limited to establishing the cause, manner, time, place and circumstances of death, as well as the identity of the deceased, police said.

The judge may make recommendations to prevent similar occurrences but is prohibited, under the act, from making findings of legal responsibility.

With files from the CBC's Stephanie Prues