TORONTO -- Ontario's police watchdog says it will not charge a Peel Regional Police officer who last year shot and killed a 33-year-old man after a traffic stop northwest of Toronto.

And that has left Jermaine Carby's family outraged.

"We kind of expected this decision," said La Tanya Grant, Carby's cousin and family spokeswoman. "We're going to move forward with our civil lawsuit."

The Special Investigations Unit's director, Tony Loparco, said in a lengthy news release that three Peel officers feared for their lives before one shot and killed a knife-wielding Carby in Brampton, Ont., last September.

"I am satisfied that the officer discharged his firearm at Mr. Carby for the purpose of protecting and defending himself as well as other officers," Loparco said.

The SIU investigation found that Carby was shot in the chest, forearm and back, with both the shots to the chest and back described as fatal hits by a pathologist.

Loparco cautioned, however, that there were two issues with the investigation.

First, he wrote, the scene wasn't secure because SIU officers couldn't find the knife witnesses said Carby was holding at the time he was shot. A kitchen knife was turned over several hours later by a Peel sergeant who said an officer had bagged it after removing it from Carby's hand as he lay on the ground after the shooting.

"It is highly regrettable that one officer removed the knife from the scene," Loparco wrote. "His ill-advised conduct has cast a pall over the integrity of the SIU's investigation ... the removal of the knife ensures that some members of the community will harbour concerns, legitimate concerns in my view, regarding the very existence of the knife."

Grant is incensed at the SIU's findings.

"Pardon my French, but how much more bullsh-t could the story get?" Grant said to The Canadian Press on Tuesday night.

The second issue that concerned Loparco was the officer's refusal to be interviewed or hand over his notes of the shooting, as is his legal right.

Grant questioned the officer's motives.

"If you have nothing to hide, why wouldn't you want to provide your notes unless you don't want to say what really happened that night?" she said.

A spokesman said Peel Regional Police "agree with the conclusion the officers were justified and lawful in their actions."

"All the involved officers are relieved this matter has been finally concluded," Sgt. Matt Small told The Canadian Press in an email Tuesday night, calling it "a tragic event for all involved."

Loparco wrote that, despite his concerns, he was satisfied with the evidence from interviews with six officers and 12 civilian witnesses. He also said that Carby's DNA was present on the knife.

Loparco said Carby was a passenger in a black Volkswagen Jetta that was pulled over by police in Brampton, Ont., because the car's lights weren't on and it had a dangling, obscured licence plate.

The first officer asked Carby for his name and date of birth, and a subsequent database search revealed an outstanding warrant in British Columbia, Loparco said.

The officer then called for backup and waited in his cruiser to approach when other officers arrived, including the one who would end up shooting Carby.

Three officers asked Carby to get out of the car, which he did, the SIU investigation determined.

But the SIU said the encounter quickly degenerated into a shouting match.

Carby then pulled out a serrated kitchen knife and began walking toward the officers, the SIU said.

The officers yelled at Carby to drop the knife, "but he kept walking toward them, all the while challenging the officers to shoot him."

One officer fired his gun seven times, striking Carby three times, including his chest and his back. Another officer said he tried to shoot Carby, but his gun misfired twice.

"Potentially more troubling is the fact that one of the shots fired by the subject officer struck Mr. Carby in the back," Loparco wrote, adding that witnesses described Carby as twisting and spinning as he was shot and falling down.

Grant said the family has hired a private investigator and will continue to "pursue the truth to what really happened that night."