A security hood assembly for a holster includes a hood that is movably supported in association with a holster body so that the hood extends over a portion of a holstered handgun or other service item when the hood in a closed position, to prevent unauthorized removal of the service item. A lever may be operably coupled to the hood for driving the hood toward an open position, to allow the service item to be removed from the holster. In some embodiments, a latch mechanism releasably engages when the hood is in the closed position to prevent the hood from being opened through direct manipulation of the hood. The hood is preferably formed of a substantially rigid material, such as injection molded plastic. Holsters including the security hood assembly may also include internal retention devices, hood biasing mechanisms, and electronic devices responsive to opening of the hood.