CPD Officer John Rivera, 23, was inside his car at the former Rock-n-Roll McDonald's in River North back in 2019 when he was shot and killed.
Jaquan Washington pleaded guilty to conspiracy to commit first-degree murder and was sentenced Tuesday.
Police say Rivera may have been mistaken for someone else.
Another man, Jovan Battle, was also found guilty in the murder and is currently serving a 65-year prison sentence.
SEE ALSO | 3rd suspect charged in fatal shooting of Chicago Police Officer John Rivera
READ MORE | Former supervisor remembers Chicago police officer John Rivera killed in River North in emotional Facebook post
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