Police say two U.S. Marshals were escorting a police chief from Belize, who was in town for the gang summit.
They walked into the AutoZone where a robbery was under way. They encountered a suspect holding a butcher knife and a large amount of money.
The Marshals say he lunged at them and one of them shot him.
There's no word on the suspect's condition.
Officials are searching for another man at the scene who may be a second suspect.
