The title may smack of some kind of slimy horror film, but Dan Gilroy’s Nightcrawler, with Jake Gyllenhaal in the title role, is mostly a nocturnal character study with a darkly satirical edge to it. And the slime in this case is metaphorical, while the chief horrors are moral and psychological. The nightcrawlers of this tale are the freelance photojournalists who deal in sensationalistic video footage of crime scenes, traffic smash-ups, and any local calamity gory enough to grab the attention of TV broadcasters. Gilroy’s movie puts primary focus on one Louis Bloom (Gyllenhaal), a perversely adept newbie who finds a market for his lurid footage in Nina Romina (Rene Russo), the news director at a ratings-starved TV station. Gyllenhaal is superb with a character who seems nerdy and naive even when his actions have lethal consequences. Bloom is thoroughly enterprising and industrious as well as habitually indifferent to an ever-growing list of moral, ethical and legal distinctions, and ultimately he seems more like a satirical concept than a fully realized human character. But the concept and the satire have some very sharp and brilliant edges.