Akron police say a 17-year-old male shot and killed himself in the back seat of a police cruiser on Friday night. Police haven't said how the gun used by 17-year-old Xavier McMullen ended up inside the cruiser. The shooting occurred after the teen and two 18-year-old men were arrested for an earlier armed robbery and were placed in separate cruisers. Akron Mayor Dan Horrigan says he has requested and received the resignation of police chief James Nice for conduct unbecoming of an officer. It is unclear if the resignation is related to McMullen's death.