Montreal police started a criminal investigation Thursday into the on-ice hit by Boston's Zdeno Chara that left the Canadiens' Max Pacioretty with a severe concussion and cracked vertebra.
Police said they are acting on a request by Quebec's director of criminal and penal prosecutions, Louis Dionne. Police added that after evidence is collected it will then be determined if there are grounds for prosecution.
The NHL said a day earlier it would not suspend Chara for Tuesday night's hit, when he slammed Pacioretty into a glass partition.
NHL Commissioner Gary Bettman declined to comment Thursday while on his way to a congressional briefing in Washington, D.C. focusing on the state of hockey in America.
There has been strong debate this season over injuries from hits to the head. Pittsburgh star Sidney Crosby is among those sidelined with such an injury.
In a related matter, Air Canada has told the NHL it is considering withdrawing its sponsorship unless the league tightens rules to reduce potentially serious injuries.
Dionne filed his request for an investigation after watching television footage of Chara's hit, his spokeswoman said.
"The police investigation will be held. Like all police investigations, evidence will be gathered and an investigation report will be submitted, spokeswoman Martine Berube said. "(The DCPP) will then evaluate to see whether there's grounds for prosecution."
Asked what kind of punishment could be assessed in a case like Chara's, she replied: "It's too early to say. That would depend on what charges are laid. That's a little difficult to predict at this point."
Pacioretty, a left wing from Connecticut, is a regular top-line player for Montreal. With he and Chara racing for the puck near the player benches, Chara checked Pacioretty into the boards, sending him slamming into a stanchion supporting the glass.
The hit drew criticism from Gary Lunn, the minister of state for sports, and others outside the league. Lunn called it unacceptable.
But the league deemed it "a hockey play that resulted in an injury because of the player colliding with the stanchion and then the ice surface."
Chara, who said he had no intent to hurt Pacioretty, was given a major penalty for interference and a game misconduct on the play. The Bruins' captain has never been suspended in his 13-year career.
Pacioretty told TSN he was "upset and disgusted" that the league had not suspended Chara.
"I'm not mad for myself, I'm mad because if other players see a hit like that and think it's OK, they won't be suspended, then other players will get hurt like I got hurt," he said.
(This version CORRECTS spelling to vertebra)