Maricopa County Sheriff Joe Arpaio says 50-year-old deputy William Coleman and his partner found a suspect in a van at a medical building at about 4 a.m. Sunday.
The 40-year-old man got out of the van and opened fire with an assault rifle, striking Coleman under his bullet-proof vest. The deputy was taken to a hospital but doctors could not save him.
The suspect was shot and killed by other deputies. Arpaio says investigators are trying to determine why he opened fire.
Coleman was a 20-year veteran. He leaves a wife and two young children, ages 4 and 7. Arpaio says he also has grown children in another state.
