Toronto police investigators say they believe they have identified the alleged trigger man behind a “brazen” nightclub shooting in North York over the August long weekend that left four people injured.

At 2:15 a.m. on Aug. 5, police were called to District 45 nightclub in the Finch Avenue West and Keele Street area for multiple reports of shots fired inside.

Two male victim and two female victims were struck by gunfire.

One was treated for life-threatening injuries while injuries to the other three were considered serious.

Investigators said the shooting occurred in the rear section of the club, where they located multiple shell casings.

Witnesses told CP24 at the time that they saw gun smoke in the club and scrambled for the exits when gunfire erupted.

The shooting represented the worst single incidence of gun violence in an otherwise awful weekend for gunplay in Toronto, where a total of 16 people were injured in shootings.

On Aug. 12, police arrested a suspect who allegedly manufactured his own handgun and pistol ammunition.

On Friday, police identified a second suspect in relation to the incident.

He was identified as Matthew Costain, 34, of Toronto.

He is described as six-feet-tall, 245 pounds, with a heavy build. He is bald and may be sporting a beard.

He is sought for two counts of discharge a firearm with intent, two counts of aggravated assault and weapons offences.

Anyone with information is asked to call police at 416-808-3100.