A New York Police Department officer who was killed on duty Sunday was shot by friendly fire. Police Department Commissioner James O'Neill and Chief Kevin Maloney said in a Monday press conference that 33-year-old Officer Brian Mulkeen was struck twice by other officers while investigating gang activity. Mulkeen and his partners were attempting to question two suspects, one of whom fled on foot, leading to a chase. During the struggle, the suspect reached toward his waistband before Mulkeen’s partners fired 10 rounds. Two of the rounds hit Mulkeen, and he died after being transported to a hospital. Five of the rounds hit the 27-year-old suspect who fled, and he also died at a hospital. Officials say a .32-caliber revolver believed to have belonged to the suspect was recovered at the scene and was not fired during the incident. “This is a tragic case of friendly fire, but make no mistake, we lost a life of a courageous public servant solely due to a violent criminal who put the lives of the police and all the people we serve in jeopardy,” O’Neill told reporters. Mulkeen is the second NYPD officer killed by friendly fire this year.