It happened about 10am in a strip mall parking lot in the 7500 block of South Lindbergh in South St. Louis County. Authorities believe the suspect came into the state office building at the corner of the parking lot to find Dunn. Police Public Information officer Shawn McGuire said the two males walked outside together and at that point the suspect pulled a metal bat from his clothing and began attacking Dunn.
He was struck repeatedly in the head until witnesses intervened and the suspect dropped the bat to the ground. He then sat down next to the body and waited for police to arrive. Police say he did not resist arrest. Mr. Dunn was pronounced dead at the scene.
A variety of state agencies including child support, senior health services, disability and the Department of Natural Resources have offices in the building. State authorities referred all questions to St. Louis County Police.