The Toronto police officer who fatally shot 45-year-old Andrew Loku in July 2015 will not face any criminal charges, the Special Investigations Unit said Friday.

"I am satisfied that the subject officer fired his weapon believing it to be necessary to thwart an imminent hammer attack and that the officer's apprehensions in this regard were reasonable," SIU director Tony Loparco said Friday in a news release.

Three investigators and three other forensic investigators were assigned to probe the incident. They determined that the officer did not exceed "the ambit of justifiable force in the circumstances."

The investigation found that Loku was shot by police around midnight on July 5 at an apartment complex near Rogers Road and Caledonia Road after he refused to comply with demands to drop a hammer and threatened to kill a friend of a guest in the apartment.

The officer who would eventually shoot Loku and a second officer entered the building and confronted Loku, with guns drawn, in a third-floor hallway.

The investigation found the officers were eight to nine metres away from Loku when they ordered him to drop the hammer. Instead of complying, he began walking in their direction.

According to the release, Loku reportedly said, "What you gonna do? Come on, shoot me."

Loku apparently then raised the hammer above his head. He was two to three metres away from the officer in question when he was shot.

A postmortem confirmed Loku's cause of death to be gunshot wounds to the left chest.

'Duty to preserve and protect life'

According to Section 25(3) of the Criminal Code, an officer's use of lethal force in the execution of duty is limited to cases where such force is reasonably necessary to protect against loss of life or grievous bodily harm, Loparco said in the release.

Section 34 further indicates the amount of force that may be used in self-defence or the defence of others, but is more general in application, he continued.

"There is no question that the officers were acting in the discharge of their duty to preserve and protect life when they made their way to the third floor and confronted Mr. Loku," Loparco said. 

"They had received word of an assault in progress involving a man armed with a hammer threatening a woman with death and refusing to leave her apartment. From that moment, it was a matter of seconds until the shooting, at which time I have no doubt that the subject officer feared for his life and that of his partner." 

Loku's death set off a firestorm of controversy and prompted Toronto's Black Lives Matter coalition to call for charges to be laid against the officers involved in the shooting. The group also wanted the officers involved be identified and video footage of the incident to be made public.

The organization also called for monetary compensation for Loku's family and public apologies from the mayor and police chief.

Ontario's Special Investigations Unit (SIU) is an independent civilian law enforcement agency that investigates cases of death, serious injury or sexual assault involving police. SIU probes also limit what Toronto police can say about the incident.