The film Gangster Squad is based on the life of Mickey Cohen, a well-known 1949 gangster, friend to Frank Sinatra and accomplice to Al Capone and Bugsy Siegel (subject of the film Bugsy in which Mickey is played by Harvey Keitel). Mickey's life was threatened on several occasions to the extent he had to drive around in a bullet proof car.

Although the film is based on a real life, not everything in it is true, this is a film and it has to work in that genre to be worth watching. However, having seen the film you may wonder what he did get up to that is not shown - single incidents in the film are often an amalgamation of many and often frequent occurrences.

Sean Penn, is portraying him in this blockbuster, and, although not a great success with critics, the audience seem to have enjoyed the film.