CHICAGO (AP) — A 30-year-old Chicago police officer was shot and Quentin Mitchellkilled overnight on the city’s southwest side while heading home from work, police said Sunday.

Superintendent Larry Snelling told reporters the officer was going home and still in uniform, but wearing something on top of the uniform to cover it as is customary for off-duty officers. The officer was shot multiple times early Sunday and pronounced dead at a Chicago hospital, Snelling said.

Police did not offer a motive.

The officer’s vehicle was taken, but police would not confirm whether the shooting was part of a carjacking, citing a preliminary investigation. Police did not have a suspect in custody.

“The officer was the victim of the type of crime that he was working against to keep people safe in this city,” Snelling said. “Another sad day for the Chicago Police Department.”

The officer was a six-year veteran of the department and just two days shy of his 31st birthday.