Mayerthorpe tragedy
Roszko shot and killed four Royal Canadian Mounted Police (RCMP) constables: Anthony Gordon, Lionide "Leo" Johnston, Brock Myrol and Peter Schiemann.
The attack occurred as the officers were executing a search warrant for stolen property and a marijuana-growing operation on the farm.
Two individuals who were not present at the shooting, Shawn Hennessey and Dennis Cheeseman, pled guilty to manslaughter for assisting Roszko to return to his farm.
They left the quonset at approximately 4:15 pm and called in the truck as stolen, warning that other officers should be on the lookout for Roszko.
The initial focus was on the search and seizure of the marijuana plants and equipment, conducted by a special "Green Team" from the RCMP "K" Division in Edmonton.
[5] All but two Mounties left at that point, with the expectation that an RCMP team which specialised in stolen vehicle searches would arrive in the morning.
As a security measure during the night, the Mounties had parked several marked police vehicles prominently in the farmyard with their lights on.
They also left the vehicle doors and man-door of the quonset wide open, with bright halogen lights on inside.
He had decided to hide the truck at his aunt's home, and asked Hennessey and Cheeseman to follow him there, then drive him to his own farm.
[12] On the morning of March 3, 2005, Constables Anthony Gordon and Leo Johnston were still providing scene security, pending the arrival of the RCMP Auto Theft investigators.
Corporal Martin decided to send Constable Myrol to the scene to assist with the search by the Auto Theft investigators.
They also agreed that they would pick up some meat and a veterinary sedative to feed and calm down the dogs, who had not been fed since they had been put in the shed the day before.
Outside the quonset, Constables Hoogestraat and Vigor heard two loud bangs, followed by several other sounds which they recognized as gunfire.
[15] The Emergency Response Team sent in a Remote Mobile Investigator, a robot with a video camera attached, and determined that all four officers and Roszko were dead.
He was stationed in Whitecourt, 45 km (28 mi) west of Mayerthorpe, where he was assigned to general policing and highway patrol.
From Petrolia, Ontario and raised in Stony Plain, Alberta, he began his career in Mayerthorpe and was assigned to general policing and highway patrol.
His truck was found at his aunt's residence, 38.5 km from his own farm, suggesting he had received some assistance in returning.
These search techniques disproved local rumours that Roszko had major caches of drugs and weapons, or that there were tunnels which he had used to enter the quonset.
[28] The search found a sheet, a pillowcase containing a pair of workgloves, a small bottle of water and a tin of bearspray in the northeast corner of the quonset.
The Fatalities Inquiry concluded that Roszko had likely concealed himself at that spot for some time, but had actually been in the southeast corner of the quonset when he fired the shots.
The Fatalities Inquiry surmised that the Heckler & Koch rifle had been hidden in this area and retrieved by Roszko after his return, since he did not have it when he was with Hennessey and Cheeseman.
John Hennessey admitted that he had told his daughter and grandson that they should all "story" to the police that the rifle had been stolen from the back of his welding truck.
[38] In June 2008, they were committed to stand trial on the murder charges after a preliminary inquiry in the Provincial Court of Alberta.
[32][33] On January 30, 2009, the Queen's Bench gave its decision on the sentences for the two men, which was based on an Agreed Statement of Facts, signed by Hennessey, Cheeseman, their lawyers and the Crown prosecutors.
The Court gave them credit for their early guilty pleas and for time served awaiting trial, which reduced those initial estimates.
[49] On May 19, 2005, Queen Elizabeth II attended a ceremony in honour of the slain officers at the RCMP Academy, Depot Division, in Regina, Saskatchewan.
The group initiated the building of the Fallen Four Memorial Park in Mayerthorpe, with a statue of each officer, which opened on July 4, 2008.
[53] Following the 2009 guilty pleas and sentencing of Cheeseman and Hennessey, the fifth estate did a second documentary, entitled "Collateral Damage", which aired on February 4, 2009.
He now denied some of the material in the Agreed Statement of Facts which had been used in the sentencing hearing in Queen's Bench five days earlier.
The report provides a detailed factual account of the killings, and also made eight recommendations to prevent a similar event from occurring in the future.
