Lawless (2004)

A killer escapes justice on a technicality, and a senior police officer proposes that he and his colleagues take justice into their own hands. When the officer is murdered, the innocent DI John Paxton is blamed and goes on the run.

DI John Paxton, implicated in the murder of his boss, is on the run, and trying to find the real killer, but Keeney, the only man who could help establish Paxton's innocence, has been drowned.