Jake Gyllenhaal is Lou Bloom, a petty thief in the Los Angeles dark whose shamelessness — specifically his lack of anything like a moral compass — becomes an enormous asset when he manages to get a foothold in the straight world. Pawning a fancy bicycle (was it stolen?) in exchange for a camcorder and a police scanner, he joins the ranks of the video shooters who prowl at night, angling for close-up footage of bloody meat on the city streets.