Pacioretty broke a vertebra and was out for the season after being shoved into a stanchion by Boston's 6-foot-9 defenseman in March.
The provincial prosecutors' office said in a statement Thursday that it does not believe a court would find Chara guilty of a crime and it has closed the case.
Bruins president Cam Neely issued a statement Thursday night saying the team also considered the matter closed and would have no further comment.
Chara received a game misconduct but was not suspended. The ensuing uproar in Montreal prompted the police investigation.
Montreal police interviewed various witnesses and concluded their investigation in August after meeting with Chara.
Pacioretty was critical of the NHL's handling of the incident, but had called police involvement unnecessary. He has returned to play this season.