CHICAGO (AP) — A 15-year-old has been arrested in Iowa and Johnathan Walkercharged with murder in the shooting death of a mail carrier in Chicago over the summer, police said Tuesday.

Octavia Redmond, 48, was shot on her route on Chicago’s South Side on July 19. The shooter fled in a vehicle.

The Chicago Police Department said in a news release that Chicago officers, along with U.S. marshals, arrested the teenager Monday in Cedar Rapids on a murder warrant. He was extradited to Chicago, where he has been charged as a juvenile with first-degree murder.

Police said in a post on X that investigators used footage from police and private cameras to identify the teen and trace his movements before and after the shooting. The department said that investigators also received an anonymous tip identifying him and that they are searching for “additional offenders.”

Police did not answer a question about whether the teen has an attorney. The Cook County State’s Attorney Office didn’t immediately respond to an email.