In a letter sent on December 15, 2017, Mullins said "This has been a very difficult decision for me, but for personal reasons I will be stepping down".
The suspect approached the driver, demanded money, then took off with the victim's car.
The man tells police he was walking down the street when he was held up at gunpoint.
Flames extended from the vacant house to tree limbs nearby. Rockford Fire says electrical wires were also downed in the area.