Big Little Crimes tells the remarkable stories of ordinary beat coppers who stumble upon a key piece of evidence — a haul of stolen goods, a suspect on the run — and bring a major criminal to justice. The simple stop-and-search of a suspicious man leads to the arrest of a serial killer. A copper's decision leads to an armed stand-off in an isolated beauty spot, and a road traffic collision leads to the discovery of a massive fraud with thousands of victims.