(West Greenwich, RI)--The Rhode Island Department of Environmental Management says an incident involving an officer firing his gun is being investigated.The DEM says the officer had been struck and injured by a man on a dirt bike in the Big River Management Area in West Greenwich at around 12:30 p.m. Saturday.Authorities say a Coventry man, Austin DiPeitro, was arrested on charges including assaulting a police officer.The officer involved was reportedly taken to Kent County Hospital by ambulance.