the idea was, to kill a vampire you stake 'em. carrying around a lot of stakes is kinda problamatic when your an undercover Unit. so.. they used compressed charcoal/graphite bullets so they could stake 'em fast and without fuss. well, until the damn things would explode and take out the immediate 10 feet or so.. another innovation was the camera system. vampires in Ultraviolet would'nt show up in mirror's, on video feeds or on microphones. so, attached to the guns they used was a small camera and videoscreen. the idea being a mortal would show up on the screen if the gun was pointed at them, a vampire would just show the background.. Ultraviolet was a bloody interesting and deep show (I ahve them on DVD) shame they never made a 2nd series :(