Joseph P. Bergl was a mechanic who supplied specially designed vehicles for Chicago's underworld including Al Capone

Al Capone

Alphonse Gabriel "Al" Capone was an American gangster who led a Prohibition-era crime syndicate. The Chicago Outfit, which subsequently became known as the "Capones", was dedicated to smuggling and bootlegging liquor, and other illegal activities such as prostitution, in Chicago from the early...

's Chicago Outfit

Chicago Outfit

The Chicago Outfit, also known as the Chicago Syndicate or Chicago Mob and sometimes shortened to simply the Outfit, is a crime syndicate based in Chicago, Illinois, USA...

 to Depression-era outlaws George "Machine Gun" Kelly

Machine Gun Kelly

George Kelley Barnes , better known as "Machine Gun Kelly", was an American gangster during the prohibition era. His nickname came from his favorite weapon, a Thompson submachine gun. His most famous crime was the kidnapping of oil tycoon & businessman Charles Urschel in July 1933 for which he,...

 and members of the Barker Gang.

Operating from his garage Bergl Auto Sales on 22nd Street, next to Ralph "Bottles" Capone

Ralph Capone

Ralph "Bottles" Capone, Sr., was a Chicago mobster and an older brother of Al Capone. Ralph Capone got the nickname "Bottles" from the fact that he lobbied the Illinois Legislature to put into law that milk bottling companies had to stamp the date that the milk was bottled on the...

's Cotton Club

Cotton Club

The Cotton Club was a famous night club in Harlem, New York City that operated during Prohibition that included jazz music. While the club featured many of the greatest African American entertainers of the era, such as Fletcher Henderson, Duke Ellington, Adelaide Hall, Count Basie, Bessie Smith,...

, Bergl would supply Capone's organization with custom made cars for both protection and evasion purposes including armor plated vehicles with bulletproof windows as well as creating oil slicks, smokescreens, and other devices designed to elude police pursuit.

Members of the Barker Gang used such a car robbing Federal Reserve Bank messengers at Jackson Boulevard on September 22, 1933. After a patrolman was killed, the gang fled the scene with a load of canceled checks and eventually forced to abandon their car after crashing it.

Upon finding the wrecked car, police traced the vehicle to Bergl's shop and arrested Gus Winkler

Gus Winkler

Gus Winkler was a St. Louis mobster who, with Fred “Killer” Burke, was head of a criminal gang specializing in armed robbery and murder for hire....

, member of the Chicago Outfit and Bergl's silent partner, naming the Chicago gangster of being a member of a national armed robbery syndicate, supposedly including Depression-era bandits George "Machine Gun" Kelly and Vernon Miller.

Winkler would be killed in a gangland slaying by unidentified gunmen on October 9, reportedly suspecting Winkler would turn states evidence in exchange for reducing the long prison sentence faced by the charges. Although Bergl was allowed to live, the exposure to law enforcement officials ended his usefulness to the crime syndicate as criminals would turn to competitor Clarence Lieder

Clarence Lieder

Clarence Lieder was a mechanic and armorer for Chicago's underworld and Depression-era criminals, as well as the primary competitor to Joe Bergl...

.