Officially, Law Abiding Citizen isn’t a horror film. But it starts out with something that would be at home in the rape-revenge horror category, a home invasion, murder of wife and daughter by creepy dudes. Then we get some courtroom bits, dealing with the system, and how people make deals. After that, we get the fun of the main dude beginning his revenge. Swapping the lethal injection chemicals for something messier, multi-limb amputation of the accomplice who made a deal to get off on lesser charges. And then we get into his revenge on the system. Bombs, killer robots, and more bombs. In the end, he gets tricked and hoisted by his own petard; or roasted by his own napalm, rather.