STATEN ISLAND, N.Y. — A firefighter pleaded guilty to assault in the third degree after he punched and used a chair to strike a colleague at the Rescue 5 firehouse in Concord last summer.
Christopher Mullin, then 53, of Hoyt Avenue in West Brighton, faced multiple charges in connection with the assault on Aug. 8, 2025.
According to a law enforcement source, the dispute began when Mullin told the 62-year-old victim to mop the floor while the victim was doing other tasks. The two had worked together for more than 15 years…