Montreal police are seeking to determine the motive behind a murder in an apartment building on Henri Bourassa Blvd. at the corner of St. Laurent Blvd. in Ahuntsic-Cartierville.

The 57-year-old victim was found lying in a pool of blood in a hallway of the building at 7:15 Thursday morning. Police say his injuries were a result of a physical altercation – one so violent that it was initially impossible to determine how he was attacked.

“We're still looking at everything at this moment. We'll know with the autopsy what caused the injuries – was it a knife? Was it a gunshot? Was it just fighting? All that information will have to be gathered,” explained Jean-Pierre Brabent of the Montreal police.

The people who found the victim called 911 and he was rushed to hospital where he died of his injuries.

Montreal's major crimes squad is investigating.

There were several video surveillance cameras in the building and in the neighbourhood

Police are reviewing their content, but have yet to arrest a suspect. 

For much of the day, police kept the fourth floor of the building under lockdown so they could interview tenants individually.

“Everyone on the fourth floor was questioned to see if they saw something, if they knew something about either the victim or people that were coming inside the apartment,” said Brabant.

This is the 21st murder of the year on the island of Montreal.