Montreal police started a criminal investigation Thursday into the on-ice hit by Boston defenseman Zdeno Chara that left the Canadiens' Max Pacioretty with a severe concussion and cracked verterbra. 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 then will 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 near the edge of the Bruins' bench.