A 22-year-old man armed with a rifle and wearing a ballistic vest “waited in ambush” for police to arrive at his Innisfil home last October before he fatally shot two officers, according to a report from Ontario's police watchdog.

The Special Investigations Unit (SIU) released on Wednesday its findings into the Oct. 11 shooting that left 33-year-old Const. Devon Northrup and 54-year-old Const. Morgan Russell of South Simcoe Police.

While the report by SIU Director Joseph Martino focused on the interaction between police and the man who died of a self-inflicted gunshot wound, it provides a timeline of the events that led to the deaths of the two officers using evidence gathered at the scene, materials obtained from three police services and video footage from witnesses.

FULL REPORT: SIU Concludes Investigation into Self-Inflicted Death of Man in Innisfil After Exchange of Gunfire with South Simcoe Officer

The SIU said South Simcoe Police officers were dispatched to a residence in the area of 25th Sideroad and 9 Line after receiving a call from a woman who wanted a 22-year-old man, referred to as the complainant in the report, removed from her home.

The complainant was previously identified by family friends, and his ex-girlfriend as Chris Doncaster.

Chris Doncaster

The woman told police that Doncaster had grabbed her eyeglasses from her face and broken them. She also reported that he had punched a hole in the wall. When asked by the operator if Doncaster had been drinking and whether weapons were involved, the woman said, “nope.”

The SIU said the complainant lived in the home with two family members, one of whom was the woman who wanted him to be removed. The agency noted that contrary to what the woman told police, Doncaster had, in fact, consumed alcohol and had access to firearms, including an SKS 7.62x39 mm semi-automatic rifle located in a safe in his basement bedroom.

Three police officers arrived at the home in separate cruisers, according to the report. One of them is referred to as the subject official (SO). The other two were Northrup and Russell.

The SO rang the doorbell and was invited inside by someone within the home, the SIU said. The officer entered, followed by Northrup and Russell.

According to the SIU, the officers were met with two sets of stairs when they got inside the home. To their right was a flight of stairs to the basement, while on the other side lead to the upstairs level.

“The SO had just reached the upper step and met with a man – (referred to the report as civilian witness # 4) – when he heard gunshots ring out,” the SIU said. When the officer looked back, the SO saw Northrup and Russell down on the floor with apparent gunshot wounds.

The SO drew his sidearm, reached over the railing and began shooting down the basement stairs, the SIU said, adding that he fired 12 to 14 rounds before pausing and reloading.

The officer then called out “police” but got no response, the SIU said. He subsequently looked down and saw Doncaster, who was “on his back in a pool of blood, a rifle in his hands.”

The SIU said Doncaster had fired up 11 times on Northrup and Russell using the SKS rifle.

SKS semi-automatic rifle

“Neither of the officers had their weapons drawn at the time,” the SIU said.

“Shortly thereafter, still in the basement within a few metres of the foot of the stairs, the complainant placed the muzzle of the rifle under his chin and fired the weapon. The round travelled through his head and upwards to the kitchen on the next floor, coming to rest in the cupboard underneath the sink.”

An autopsy determined that Doncaster died due to a “submental gunshot wound to the head – contact range.”

Meanwhile, despite life-saving measures, Northrup and Russell died from their injuries.

In his analysis, SIU Director Martino said there are no reasonable grounds to charge the officer as there is nothing in the evidence to indicate that a criminal offence was committed.

“While wearing a ballistic vest, the complainant had waited in ambush for the police officers to arrive at his residence and then fired at the officers multiple times, mortally wounding (Northrup and Russell). In the circumstances, the officers were clearly under attack at the time that the SO drew his weapon and returned fire down the stairs into the basement,” he wrote.

“His decision to do so was commensurate with the exigencies at hand. It was imperative in the moment that the SO do what he could to immediately deter the Complainant from continuing to fire his weapon, and the officer’s gun was the only weapon at his disposal capable of doing that.”

Martino noted that before losing consciousness, one of the two officers shot was able to tell the SO where the shooter was by pointing to the direction of the basement.

“Regrettably, given the speed with which events unfolded, the damage had been done to (Northrup and Russell) before the SO could react. That said, the force used by the officer – which did not kill the Complainant but appears to have caused a graze wound to his lower left leg - might well have saved his own life, as well as those of the Complainant’s family members, who were nearby at the time,” Martino wrote.

South Simcoe Police Chief John Van Dyke released a statement, saying his force is relieved that the SIU investigation has concluded.

"Of course, no investigation can ever bring back our beloved fallen officers, Morgan Russell and Devon Northrup, but at least we can now close one chapter of this tragedy," Van Dyke said.