Law abinding citizen

After a plea bargain frees one of his family's killers, a frustrated man decides to take justice into his own hands.

Clyde Shelton's family is assassinated. The perpetrators have been apprehended. However, because to poor protocol, the District Attorney, Nick Rice, has only circumstantial evidence. As a result, he plans to have one of them testify against the other. Shelton is furious when he learns of this. Ten years later, the guilty person is about to be killed, but something goes wrong; his execution goes wrong, and he suffers.

They discover that the machine has been tampered with. And the other is discovered dead, murdered in a heinous manner. Rice suspects Shelton and has him arrested. Shelton first agrees to a plea arrangement with Rice but then changes his mind. Shelton does not appear to be finished; he appears to be blaming the entire system and declaring war on it, going after everyone involved in his family's case. Rice must thus stop him, but Shelton is well ahead of him.