Gangster Squad is loosely based on the true story that the Los Angeles Police department had an undercover hit squad to taking out organised crime by any means. Tales of such unit have been the subject of films before. The complication in this story is also not new with the main characters wife and family under threat and another character, something of a play boy becoming involved with the woman Emma Stone of the gangster leader Sean Penn. Nick Notle plays the honest police chief. The film engaged for a couple of hours.