The daytime incident began when a domestic dispute arose in Maicah Park between an unidentified man, his current girlfriend and his ex-girlfriend, a news release said. The man and his current girlfriend left the reunion for an unspecified amount of time, but later returned. The man then fired, prompting an off-duty Palos Hills Police Department officer to hit him, police said. The gunman was taken to an area hospital in unknown condition and later pronounced dead, authorities said. NBC 5 has yet to independently verify the account of events provided by the South Holland village. No bystanders were injured in the shooting. Anyone with information is asked to contact South Holland Police Department detectives at 708-331-3131 ext. 2.