DETROIT (WLS) --

A man dressed as a guard walked away from an armored car robbery with more than half-a-million dollars.

The robbery happened outside a casino in Detroit.

Police say the man didn't appear to have a getaway car nearby. Authorities are not quite sure why the truck was at the casino because there wasn't a money drop or pickup scheduled.

Casino security and local police describe the heist as bizarre and are both actively investigating.