Flawnego, an upscale clothing store, is owned by Ducarme Joseph. (Google Streetview)Montreal police arrested the owner of a clothing boutique where deadly shootings took place as homicide detectives finished combing through the blood-spattered crime scene Friday.

Police did not immediately identify the suspect, but said a 41-year-old man had been arrested and was accused of violating bail conditions.

Police sources said the man arrested was Ducarme Joseph, who owns Flawnego, a high-end boutique on St-Jacques Street in Old Montreal, where two men were killed and two more were injured on Thursday.

Joseph is scheduled to appear in court on Saturday to be arraigned on charges of having violated bail conditions related to previous charges of fraud and extortion, sources said.

Authorities continued to search for two suspects seen fleeing the scene of the gangland-style shooting that shook the city's historic waterfront business district.

Shooting connected to criminal underworld

The bold slaying in broad daylight is believed to be a response to the December slaying of the son of reputed mob boss Vito Rizzuto.

Ducarme Joseph, 41, is scheduled to be arraigned Saturday for violating bail conditions. (CBC)Masked shooters opened fire in the upscale clothing shop on Saint-Jacques Street just after lunch hour.

The boutique is just blocks away from Old Montreal's landmark Notre-Dame Basilica in a popular tourist district.

Police said they believe the brazen attack was a settling of accounts among underworld players. The victims range from 29 to 59 years of age, and three of them are known to police.

The fourth man, who is said to be in stable condition, was identified as an electrician who happened to be in the store at the time of the shooting, said police.

Organized crime experts said the retaliation is likely part of a drawn-out struggle between Montreal's reputed Rizzuto Mafia family and street gangs, and likely linked to the shooting death of Nick Rizzuto Jr.

Former crime reporter Michel Auger said Joseph is a well-known player in Montreal's street gang scene and was once a powerful ally of Vito Rizzuto, but may have had a falling out with the clan.

The attack can be seen as an escalation of the underworld conflict between the Mafia and warring factions, Auger said.

Montreal police Chief Yvan Delorme visited the scene of the crime after the shooting, where he was briefed by plainclothes officers.

Suspects used disguises for shooting

On Friday morning, police tape was strung around the crime scene at 240 Saint-Jacques St., where investigators decked in white contamination suits could be seen through the front bay window placing clothes in brown-paper evidence bags.

Blood stained the sidewalk the day after the shooting. (Canadian Press)Blood splotches were still visible on the sidewalk in front of the boutique. Investigators wrapped their work midday, allowing the street to reopen.

Authorities said they're looking for two tall, dark-skinned men, but have few other details other than that the suspects arrived and fled the scene on foot.

"Was there a car waiting for them on another street? It's possible, but we don't have a description of a car that we could give you," said Const. Olivier Lapointe.

The men were reportedly wearing ski masks and at least one of them was sporting a dreadlock wig, later found abandoned next to the nearby Transcontinental Hotel.

Police plan to canvass the neighbourhood Friday for more clues and will view video surveillance from nearby buildings.

Shooting paralyzed Old Montreal for hours

Police said dozens of 911 calls were logged Thursday just after 1:45 p.m. when the first gunshots were heard on Saint-Jacques Street near François-Xavier Street.

One victim was dead by the time ambulances arrived on the scene. Two other victims were rushed to hospital, where one died, and one was stabilized. The fourth victim was able to drive himself to the emergency room despite gunshot wounds.

At least one victim worked at the store, but Const. Daniel Lacourcière wouldn't confirm reports that the man may have been Joseph's bodyguard.

The immediate area around the store was cordoned off after the shooting, leaving many people stranded after police told them they couldn't return to their parked cars.

Mary Weinberg made a day trip into Montreal from the Laurentians and was parked near the boutique during the shooting. She had to wait five hours before being able to return to her car.

"I said to police, 'Have you any idea when we can get our car?' 'No no, we don't know,'" said Weinberg, who lives in Saint-Sauveur.

At least one nearby hotel was locked down until police could confirm there was no danger.

The deaths are Montreal's fifth and sixth homicides of 2010.