Abstract: In a preferred embodiment, the present invention relates to a hand-held or “gun/firearm mounted” electromagnetic transceiver acting as a pulsed RADAR (i.e., “Radio Detection and Ranging”) or LIDAR (i.e., “Light Detection and Ranging”) device that can detect the presence of one or many passive retro-reflectors attached to or worn by people or objects that are close or distant in a preferred angle of detection. In a preferred embodiment this device could be mounted on a gun and would alert the user if a retro-reflector is detected in the direction of fire. Additional sensors can be used to change the effective field of detection, to save energy or to provide multiple parallel sensors for these and other reasons.