CHICAGO (CBS)– Chicago Police Supt. Eddie Johnson addressed the media Saturday around noon after off-duty officer John Rivera, 23, was fatally shot in River North. 

Police confirm Rivera and three other individuals were sitting in a parked car when two men approached their vehicle near Clark and Huron Street. One man showed a handgun and started shooting around 3:30 a.m. Saturday. The offenders fled the scene.

Johnson said he was “disgusted” by the unprovoked attack against a group of individuals who went to “unwind on a Friday night.”

Johnson said Rivera, a two-year CPD veteran, worked in the 6th District with Johnson’s son. He described Rivera as “very eager to serve the citizens of this city.” He said Rivera loved going out on patrol and solving problems.

One person of interest, who is not thought to be the shooter, is being questioned. Johnson said police are looking for at least two more individuals.

Detectives are recovering video from both city and private cameras to locate the shooter, according to Johnson.

“We have very good video of this heinous attack,” he said. “Mark my words, we will find them.”