(CHICAGO) — A Chicago police officer who had just finished his shift was shot and killed early Saturday in an apparently random attack, officials said.The off-duty officer and another victim were ambushed and shot about 3:30 a.m. local time while sitting in a vehicle in the Downtown section of the city, police brass said in a news conference Saturday morning. The two shooting victims and two other people, including another off-duty police officer, had just left a nightclub, officials said.The other victim who was shot, an unidentified man who is not a police officer, was in critical condition and in surgery, officials said. He is expected to survive, police said.The two police officers, who had just finished a “tour of duty,” and the two other people had left the club and returned to their vehicle, officials said. That’s when two men approached them, said First Deputy Superintendent Anthony Riccio.”One of them pulled a gun and fired,” he said during the news conference.Riccio said there were no words exchanged.”It does appear to be random. They did not have any confrontations with anybody,” he added, referring to the police officers.Nothing was taken from the car, either, Riccio added.The shooter is still at large, officials said, but detectives are interviewing a “person of interest.”Detectives were looking for cameras that may have captured the shooting, Riccio said.”There’s an abundance of video,” he said. “Detectives are combing through that video.”The officer who died was 23 years old and would have made two years on the job in May, Riccio said.He had handled paperwork on a killing that occurred Friday night, he added.The Chicago Police Department tweeted photos showing a procession of police vehicles transferring the officer’s body to the Cook County medical examiner’s office.A spokesman for the police department, Anthony Guglielmi, called the shooting a “devastating incident.”Copyright © 2019, ABC Radio. All rights reserved.