Chicago in the 1920s: Despite Prohibition, the town is drunken, promiscuous, and violent. Anything can be bought for enough cash: booze, women — even public officials. For mobster Al Capone, nicknamed "Scarface" from wounds got in a bar brawl, it's a great time to be alive. He is America's best-known gangster and perhaps the single greatest symbol of the collapse of law and order in the United States during the Prohibition era. The FBI branded the bootlegging kingpin America's "Public Enemy #1. For agents Elliot Ness and Frank Wilson, taking down Capone is the biggest prize there is, and the two become determined to capture him any way they can.

George Francis Barnes J, better known as "Machine Gun Kelly," was an Irish American gangster during the Prohibition era. His nickname came from his favorite weapon, a Thompson submachine gun. He is most widely known for the kidnapping of oil tycoon and businessman Charles F. Urschel in July 1933, from which he and his gang collected a $200,000 ransom.

Bonnie Parker and Clyde Barrow are among the most famous outlaws in history. Murderers and hold-up artists, the pair robbed numerous banks, gas stations, and stores in rural areas and killed at least nine people during their spree. They took photographs of themselves posing together with the weapons they used during armed robberies. These photos were shown in the newspapers to give the impression the duo were enjoying a lavish lifestyle, when in fact, they lived under immense stress and were constantly on the run.