MONTREAL - The public inquiry into a fatal police shooting heard Monday that the cops involved in the incident received different treatment from investigators than civilian witnesses.

After Fredy Villanueva's killing touched off riots in the city last year, other witnesses to the shooting were kept separate from each other and questioned within hours of the August 2008 incident.

In keeping with standard police procedure, they were kept apart to prevent them from co-ordinating their stories. But no such precaution was taken with the two officers involved in the incident.

The lead investigator with Quebec's provincial police told the inquiry that the police officers were only interviewed much later, for strategic reasons.

Sgt.-Det. Bruno Duchesne of the provincial police said he wanted to interrogate the police officers last to protect the integrity of the investigation.

He said he wanted to gather all the witness accounts before taking them into an interview with the officers involved in Villanueva's killing.

Also, he said, if he'd interviewed one officer too quickly, that officer might have managed to tip the other one off to the "orientation of the investigation."

Although the delay gave the officers plenty of time to corroborate their stories, which they did not necessarily do, Duchesne said he sees no problem with his decision.

"The police, we are honest," he testified.

No criminal charges were ever laid in the case.

Villanueva was shot when he intervened in a struggle pitting two police officers against his brother and friends, in an incident that took place in a park in one of Montreal's rougher neighbourhoods.

Rioters in Montreal-North responded by torching cars, shooting a police officer in the leg, exploding propane tanks, looting stores, knocking down bus shelters, and pelting projectiles at emergency vehicles. The riots made international news.

The inquiry heard Monday that one of the officers didn't submit a written report for a month after the August 2008 killing -- three weeks later than his partner filed one.

Villanueva lawyer Alain Arsenault tried to show that the provincial police investigation was flawed from the start as it centred on a false premise that a police officer was encircled, thrown to the ground and choked.

Witness testimony, however, suggests this is only partially true. A single witness said what he saw was Fredy Villanueva grab a police officer by the collar.

The inquiry itself has been subject to a pair of delays.

It started up again Monday, after being halted by a dispute over who would pay witnesses' legal fees and after the presiding judge stepped down for health reasons.