Saint Valentine's Day massacre

The Saint Valentine's Day massacre was a mass murder that took place in Chicago, Illinois, United States, on the morning of 14 February 1929. It was the most infamous event in the history of crime in the United States.
Background.
Al Capone was the most powerful bootlegger in Chicago. By 1929 he had eliminated several of his rival crime bosses. The last one on his "list" was Bugs Moran. Capone was trying to appear as if he was retired to Florida. So Capone didn't want to be seen as starting another gang war. Instead, Capone gave the order to one of his associates, Jack McGurn, to eliminate Bugs Moran.
Massacre.
On the morning of 14 February, McGurn lured Moran and his men to a warehouse on Clark street. The bait was a stolen of whisky they could buy cheap. Seven of Moran's men were there to inspect the load. A police car pulled up outside the building and several of Capone's men dressed in Chicago police uniforms went in and pretended to arrest Moran's men. When they were lined up against a wall when the killers pulled out Thompson submachine guns and opened fire. Six of the seven men were killed. Moran himself was just arriving when he saw the police car and escaped without notice.
At this time murder was not a federal offense. Most of the killers McGurn hired were from out of town. Police departments from different cities rarely could work together to solve crimes at that time. So the killers knew if they simply left Chicago after the massacre nobody could touch them.
Results.
Newspapers ran stories of the gangster shootings and prohibition in Chicago. These were complete with detailed photographs of the murders. At first many thought the Chicago police had committed the massacre. But most people in Chicago thought Al Capone was behind the murders. Capone had an . He was at his winter home in Palm Beach, Florida when the murders took place. The suspicions finally resulted in the arrests of Vincenzio Damora and John Scalise. These were two of Capone's known . Scalise was charged with the murders after Damora came up with an alibi. But Capone murdered Scalise personally before he could stand trial. also put pressure on the FBI to arrest Capone with any charge they could. In 1931 they finally charged him with tax evasion and sent him to prison. Capone was sent to Alcatraz for eleven years. When he was finally released he was too sick to continue his crime career. He died in 1947. Prohibition was repealed in 1933 which all but eliminated bootlegging.