The Justice and Police Museum was originally the Water Police Court (1856), Water Police Station (1858) and Police Court (1886). Restored to their 1890s character, the building's heavy blocks of sandstone, spiked gates, winding steps and corridor of cells reinforce the museum's themes of crime and punishment and law and order.

The museum features a magistrates court, a recreated police charge room and remand cells, a gallery of mug shots of Sydney's early criminals and an array of spine chilling weapons. It also showcases weird and wonderful relics from notorious crimes such as the Shark Arm Murder, the Pyjama Girl Case and the Graeme Thorne Kidnapping, as well as many original objects associated with such legendary bushrangers as Frank Gardiner, Ben Hall, Captain Moonlight and Ned Kelly.

The museum presents a lively program of changing exhibitions.