EDMONTON - The RCMP's second in command says the ambush murder of four Alberta Mounties has led them to re-think how to secure a crime scene and better prepare officers to expect the unexpected.

"We've enhanced our training ... with respect to scene security, in that officers are now taught scene awareness," Senior Deputy Commissioner Rod Knecht told reporters Wednesday, a day after testifying at the Mayerthorpe fatality inquiry.

Knecht said cadets are taught to think outside the box about what could happen and what other dangers might exist, and to not get tunnel vision and focus on one specific suspect or threat.

"Be more aware of what's going on around you," said Knecht. "See the totality of your circumstances and the environment in which you're functioning."

He stressed that while those recommendations come out of the shootings near Mayerthorpe, they don't apply to how police guarded the Quonset hut in the critical hours when gunman James Roszko somehow slipped past the cordon to re-enter the massive shed and eventually kill the officers.

Constables Anthony Gordon, Peter Schiemann, Leo Johnston and Brock Myrol were shot multiple times with a semi-automatic rifle by Roszko, who then took his own life around 10 a.m. on March 3, 2005.

Knecht stressed that Roszko was an anomaly whose violent actions were off the charts in terms of predictable behaviour.

Roszko had fled the scene in his pickup truck a day earlier when police and bailiffs arrived to repossess the vehicle. Roszko was known as a loner with a violent past but had more or less stuck to himself for years.

Police then found a marijuana grow-op and stolen car parts "chop shop" in the Quonset. They began dismantling it for evidence and were guarding it overnight to make sure the crime scene wasn't disturbed.

Knecht said such suspects are usually angry at the time but soon calm down. Instead, Roszko got angrier, got a rifle and a ride back to the scene from friends, and walked back to the Quonset under cover of darkness to exact revenge.

He noted Roszko was diabolically methodical, covering himself with a white bedsheet to blend in with the snow, putting socks over his boots to muffle his footsteps, and stepping in tire tracks to avoid leaving footprints.

The bedsheet and other items were later found outside on a front corner of the Quonset, a couple of metres from the massive, open vehicle door, suggesting Roszko needed just seconds to dash inside.

"He knew every inch of that land. He was aware of the vulnerabilities of that land and he took full advantage," said Knecht.

Nevertheless, Knecht agreed the evidence showed there may have been times when the front of the large hut was unmanned.

Johnston and Gordon had initially positioned their cruisers to watch its front as well as the yard, but sometime during the night the cruisers had moved to provide a better view of the yard, but a diminished view of the Quonset.

As well, when Scheimann and Myrol arrived the next morning, there were a few minutes when all four Mounties were at the back the Quonset sedating Roszko's dogs.

"That may have been one of the occasions (when Roszko entered) but I don't think anybody really knows how he got in there," said Knecht, adding that focusing on the couldas, wouldas and what-ifs blurs the bottom line.

"In my estimation, the scene was well secured."

The lessons of Roszko live on at Depot, the RCMP training academy in Regina, he said.

Knecht added that prior to Mayerthorpe, police were already planning to create a mock rural acreage -- complete with a main house and outbuildings -- to train cadets. That came out of previous deaths of officers. After Mayerthorpe, he said, the farm yard was finally set up and a Quonset hut was added.

One of the training scenarios now involves a suspect fleeing a small farm and then returning by stealth to come after officers -- a direct result of Mayerthorpe.

Knecht agreed that aerial photos of the semi-circular metal structure, with bodies under tarps around it, has become the icon of a nightmarish day, but he said that hasn't stopped the RCMP from using it to help cadets focus.

"It is a structure that resonates with police officers," he said. "But the reality is that every day we have members out there going out into that environment where there is a Quonset.

"That just ups the game with respect to training. It's not about exposing them to issues that may be very emotional, but exposing them to the reality of policing in the 21st century."

The fatality inquiry is to conclude Friday in provincial court in Stony Plain, west of Edmonton. Judge Daniel Pahl can then make recommendations on ways to help prevent similar tragedies.