Law Abiding Citizen (2009)

A brilliant man orchestrates a series of high-profile murders that grip the city of Philadelphia - all from inside his jail cell. The prosecutor assigned to his case realizes he is the only one who can end the reign of terror.
The plot focuses on a man who, ten years after his wife and daughter are brutally murdered, returns to extract justice from the assistant district attorney who prosecuted the case against their killers. His vengeance threatens not only the man who allowed mercy to supersede justice, but also the system and the city that made it so.