Police say Richard Henry Bain from Mont Tremblant is the suspect arrested after a shooting that left a 48-year-old man dead and another man critically wounded outside a Parti Québécois election victory party last night.

Police have also confirmed both victims were shot outside the Metropolis theatre in downtown Montreal just before midnight Tuesday. They said one of the victims, with the help of police, was dragged inside the building and the door was closed. That's when the suspect tried to burn the door down, said police.

The victim has been identified by provincial police as Denis Blanchette, a 48-year-old stagehand at the theatre. Police said Blanchette was the father of an eight-year-old girl.

'It sounded like fireworks'

Eyewitness Martin Bouffard was videotaping the celebration for the CBC's Radio-Canada and heading to the back of the building when he heard a loud bang while he was trying to film the PQ leader's exit.

People left bouquets of flowers outside the theatre Wednesday morning. (Jay Turnbull/CBC)

"It sounded like fireworks. Every time we did the student protest, we heard fireworks. It was exactly the same thing. I saw some policemen with their guns in their hands rushing to the back."

Bouffard said he saw the suspect lying on the ground on his back, along with two or three policemen. He said there were two guns by his side.

"My mind was on, 'What was going to happen to the people inside?' The fire was so huge," he said.

During questioning, the suspect was transported to hospital but police did not say why or whether he's still there. They did say he is "stable."

Pauline Marois won the Quebec election and is set to become the first female premier in the province's history. (Paul Chiasson/Canadian Press)

The McGill University Health Centre (MUHC) confirmed that someone in police custody was brought to the Royal Victoria Hospital for medical examination Wednesday morning but would not provide any further details.

Police earlier said they weren't sure whether the 62-year-old suspect is an anglophone or francophone. They said he was speaking both languages.

Media reports earlier on Wednesday identified Bain as the owner of a hunting and fishing outfitter business, but the Federation of Quebec Outfitters later said he has never held the necessary licence.

Quebec provincial police are also looking into a report that a PQ member had received threatening messages prior to the attack.

The suspect, wearing a blue robe and with his face partially covered by a balaclava, was arrested outside the venue and a rifle was seized. Police confirmed Wednesday morning that two guns had been confiscated after the incident.

Richard Bain, right, reportedly posing with Celine Dion in Las Vegas in a photo from the Mont-Tremblant newspaper L'Information du Nord. (L'Information du Nord)

The shooting occurred as Pauline Marois was giving her victory speech to supporters, prompting a swift response from the Parti Québécois leader's security team and an evacuation of the concert hall.

The man shouted in French at TV cameras while being dragged toward the cruiser, "The English are waking up!" Police would only say that he spoke with an accent.

Police said the second shooting victim, a 27-year-old man, was taken to hospital in critical condition. The MUHC confirmed Wednesday afternoon that an individual underwent surgery at Montreal General Hospital and is now in stable condition.

A third man was taken to hospital and treated for shock but has since been discharged.

Condolences pour in from politicians

Reaction from politicians poured in Wednesday morning over the tragic incident.

Early Wednesday morning, the Parti Québécois released a statement from Marois, who said her thoughts are with the family and loved ones of the man who died and that all Quebecers are mourning today after this act of violence.

Marois said society cannot let violence dictate its collective choices and it's through a democratic voice that people must express them.

Prime Minister Stephen Harper said he was "angered and saddened" by the incident, in a statement released Wednesday.

"It is a tragic day where an exercise of democracy is met with an act of violence," he said

"This atrocious act will not be tolerated and such violence has no place in Canada. Canadians can rest assured that the perpetrator of last night’s events will face the full force of the law," said Harper.

NDP Leader Tom Mulcair, in St. John's for a party caucus meeting, called for a moment of silence for the shooting victims. He said he is in a state of shock after what happened.

"Our first thoughts are with the victims and their families and those that were close to them. We're going to continue to let the police do their work before commenting any further on these tragic events," he said.

NDP MP Alexandre Boulerice spoke to reporters after the meeting, denouncing the shooting.

"When democracy speaks everyone wins. When guns speak the opposite is true," he said.

Marois calling for unity at the time of the attack

The suspect allegedly entered the venue from the back as Marois was giving a jubilant address calling for unity among Quebecers. The back door was about six metres from the stage.

"I would be lying to you to confirm 100 per cent that there was no danger to her or the people inside, but the shot was fired at the back of the building," Cmdr. Ian Lafrenière of the Montreal police told reporters outside the scene.

"For us, this is considered a homicide scene," Lafrenière said. It's the city's 22nd homicide of the year.

Police searched the suspect's vehicle Wednesday morning. (CBC)

Jean Charest, the Quebec Liberal leader who is coming off his provincial election loss as a three-term premier, said he was saddened by the incident. He spoke to reporters from his former Sherbrooke riding Wednesday morning.

"It's a shock. Who would've thought something like this would happen? Especially on election night. Our thoughts are with the victims and the family, and we'll find out more today about what happened," he said.

The gunman allegedly set a fire at the rear door of the building before he was detained. Police said four or five families living in the area were evacuated from their homes due to the fire, which they said was started with an incendiary device.

Police have met with 15 witnesses and officers finished searching the suspect's vehicle, and found more of the liquid that could have been used to start a fire.

Investigators are combing social networks for clues about intent and signs of past threats.

Another man is accused of threatening Marois after circulating a Facebook invitation to celebrate the PQ victory at the Metropolis. On his profile page there is a caricature of Marois and a photograph of various weapons. The case is thought to be unrelated to Tuesday night's shooting.