Timeline

• January – Brooklyn mobster Cola Schirò disappears after being forced to pay $10,000 to Joe Masseria. After Schiro's disappearance, Joe Parrino succeeds Schiro as leader of the Brooklyn Castellammarese faction.
• January 5 – Ciro Terranova issues a press statement regarding the dramatic robbery at the Judge Albert Vitale Fundraiser dinner in New York in December 1929. Terranova claims that he is being used as a scapegoat for the split in the New York Tammany Hall political organization. He also claims to be a "man of peace" and asks to be left alone.
• February 4 – Chicago gangster Julius Rosenheim is killed shortly after agreeing to become a police informant.
• February 20 – Carlo T. Piranio, founder of the Dallas crime family, dies of natural causes. His organization is taken over by his brother, Joseph T. Piranio.
• February 26 – Bronx mobster Tom Reina is killed by a shotgun blast by mobster Vito Genovese while leaving his aunt's home. Reina is later replaced by Joe Pinzolo. Reina, an ally of Masseria, had been suspected of secretly negotiating to defect to Maranzano's organization before his death.
• March 14 – The New York State Appellate Court orders the removal of Magistrate Albert Vitale due to his ties to organized crime figures such as Ciro Terranova and Arnold Rothstein and an unexplainable $10,000 deposit to his bank account.
• March 17 – Released from prison in Philadelphia, Al Capone returns to Chicago to resume his war against mobster Joe Aiello.
• April – Raymond "Craneneck" Nugent Bank robber and killer with the Egan's Rats gang of St Louis "Vanished" in Florida.
• April – Detroit bootlegger Joseph Galbo is convicted of bribery (April 8) and sentenced to 15 months in federal prison (April 14).
• April 13 – Clinton G. Price, district attorney of Juneau County, Wisconsin and political figure within Milwaukee, is severely wounded by a shotgun blast at his home. Price dies the following morning.
• May 6- Mob boss Tony Buccola "Disappears" after alleged confrontation with organized Crime Figures {Joseph Ardizzone}. The only trace of him is his car found in Venice California. Allgedly Buccola claimed to have information in the disappearance of Frank Baumgartker who vanished November 25, 1929.
• May 31 – Gaspar Milazzo of the Detroit crime family, is shot and killed while walking through a Detroit fish market.
• June 1 – Fox Lake Massacre, Fox Lake Illinois Verne Miller killed three and wounded two men in revenge for disappearance/death of his friend Eugene "Red" McLaughlin in May 1930 by Al Capone gang. {McLaughlin body found in Chicago canal}
• June 9 – Chicago Tribune journalist Alfred Lingle is shot and killed in a train station in Chicago, Illinois. The Chicago newspapers would promise a $55,000 reward for information on the murderer. It would be rumored that Lingle had extensive connections to organized crime.
• June 30 – Thomas Somneiro, a Chicago Outfit lieutenant, is found dead in Chicago's West Side. He was strangled to death.
• July 5 – Cleveland, Ohio mobster Joe Porrello is killed, along with his bodyguard Sam Tilocco, by an unidentified gunman while dining at a restaurant owned by mobster Frank Milano. Milano would succeed Porrello as leader of the Cleveland syndicate.
• July 15 – Vito Bonventre, Underboss to Nicolo Schiro, is gunned down outside his garage in Brooklyn.
• July 31 – Thomas McNichols and James "Bozo" Schupe, two smalltime bootleggers, shoot each other to death on Madison Street in Chicago.
• August 15 – Peter "The Clutching Hand" Morello, consiglierie to Joe Masseria, and his bodyguard Giuseppe Piranio are killed by gunmen employed by rival boss Salvatore Maranzano. The gunmen possibly include the mysterious mobster known only as Buster from Chicago.
• September – Forming a secret alliance with the remnants of deceased mobster Tom Reina's organization, Salvatore Maranzano arranges to have Joe Pinzolo, the new Reina family boss, killed in early September. Pinzolo would be killed by Bobby Doyle outside the offices of the Lucchese crime family. The hit is reportedly planned by Lucchese bosses Tommy Lucchese and Tommaso Gagliano.
• September 5 – Tommy Lucchese is arrested for the murder of Joe Pinzolo. However, charges are later dropped due to lack of evidence.
• September 23 – Al Capone rival and Unione Siciliane President Joe Aiello is killed in a drive-by shooting outside a friend's home. Aiello's death eliminates a major threat to the Chicago Outfit. Agostino Loverdo is placed by Capone as head of the Union Siciliane. However, the organization's value greatly declines over the decade, quietly dissolving by the late 1930s.
• November 5 – Mobsters Steve Ferrigno and Alfred Mineo, allies of Joe Masseria, are killed by Salvatore Maranzano's gunman outside Ferrigno's home in New York. Masseria narrowly avoids the ambush himself.