The Surete du Quebec in conjunction with the Montreal Police Department's major crimes unit are still searching area around the Metropolis theatre following a deadly attack during a political victory speech.
A gunman made his way into the building and shot two men, killing one and critically injuring another, while Premier-designate Pauline Marois was making her victory speech.
He then started a fire which was quickly extinguished.
In Pictures: Photo Gallery of speech and shooting
CTV News has confirmed that the shooting suspect is Richard Henry Bain, the operator of a fishing and hunting camp near Mont Tremblant.
The man who was killed is 48-year-old Denis Blanchette, while a 27-year-old man is still in hospital.
"We cannot exclude that the person that was being targeted by this event was the elected premier," said Guy Lapointe of the SQ.
Marois was nearing the end of her speech when bodyguards whisked her off the stage.
After a few minutes of confusion first a man, then Marois herself returned to the stage to ask people to leave.
People in the audience were left wondering what had happened but it soon became apparent.
"Someone entered Metropolis through a back entrance and fired upon two people," said Constable Dany Richer of the Montreal police force.
"Afterward this man set fire to the Metropolis."
Plainclothes police officers who were in the area pursued the suspect and were able to subdue him until police arrived.
The 62-year-old man, who was wearing a balaclava and a bathrobe, yelled "C'est assez, c'est assez, this is what happens when you make trouble," as he was escorted into a police car.
Other witnesses said the man yelled out in French "The English are waking up."
On Wednesday morning police said the suspect had been armed with an assault rifle and possibly other weapons.
He is currently in hospital where he is being treated for breathing problems.
Police are also searching a vehicle found near the venue and reportedly found more weapons and canisters of fuel.
About 15 witnesses have been interviewed so far and the suspect is also due for questioning.
Meanwhile one man said that he warned police on Tuesday afternoon that an attack on Pauline Marois's life was possible.
Stephen-Guy Sevigny said he notified police and gave a written disposition to police officers from the Surete du Quebec and Montreal police by 7:45 p.m. Tuesday.
He also said that he notified the Parti Quebecois.