A man got into a 2016 black Mercedes Benz E 400, sat for a few minutes, went to the trunk, took something out and walked away.
The problem, police say: It wasn't his car and what he took were two assault rifles.
The incident happened at about 3:30 p.m. Sunday on the seventh-floor of a parking garage at a high-rise condominium in the 1000 block of Brickell Avenue.
According to detectives, the car was parked in its assigned space and the incident was captured on surveillance tape. It is not clear why there were assault rifles in the car. Police did not say who owned the car.
Detectives believe the same person may be responsible for other car break-ins in the area.
Police say they are looking for a slim man, who is about six feet tall and was last seen wearing an orange shirt, camouflage shorts and a black cap.
Anyone with information is asked to call Miami police's burglary unit at 305-603-6030 or Miami-Dade Crime Stoppers at 305-471-TIPS (8477).