Karpis was born to Lithuanian immigrants John (Jonas) and Anna (Ona) Karpavičius in Montreal, Quebec, and was raised in Topeka, Kansas.

Transferred to the Kansas State Penitentiary in Lansing, he met Fred Barker, who was in prison for bank burglary.

Growing up impoverished in a sharecropping family, all the boys soon turned into hardened criminals, robbing banks and killing without provocation.

Lloyd was sentenced to 25 years in 1922, for mail theft, and released in 1938; he was a US Army cook at a POW camp and then was murdered by his wife in 1949.

"Ma" Barker was not herself a criminal, but badgered parole boards, wardens, and governors for the release of her boys when they were incarcerated.

On December 19, 1931, Karpis and Fred Barker killed Sheriff C. Roy Kelley, who was investigating their robbery of a store in West Plains, Missouri.

At this time a myth was started that Ma Barker ruled the gang with an iron fist, but the facts do not seem to support these claims.

[6] It is purported that Ma Barker's entire reputation as a criminal mastermind was concocted by Hoover to protect the FBI's public image after federal agents discovered they had killed a 62-year-old mother.

[7][8] In 1933, on the same weekend as the Kansas City Massacre, they kidnapped William Hamm, a millionaire Minnesota brewer outside of his office.

The FBI had by this time organized a group of highly skilled agents called the "flying squads," which specialized in hunting down the leading public enemies, and they had been very effective.

The year 1934 alone saw the deaths of John Dillinger, Bonnie and Clyde, Charles "Pretty Boy" Floyd, Lester "Baby Face Nelson" Gillis, John "Red" Hamilton, Homer Van Meter, Tommy Carroll, and Eddie Green.

Karpis continued his crimes with others, but had to keep on the move more than ever, as he was the fourth and last of the FBI's Public Enemies Number One, the previous three—John Dillinger, Pretty Boy Floyd, and Baby Face Nelson—having been killed.

He did manage to pull off a crime that echoed the times of the "Old West", a train robbery in Garrettsville, Ohio, which netted $27,000.

In those days, when the application of science and technology to fight crime was still in its infancy, the agency was at the mercy of public citizens for information.

[citation needed] The capture of Karpis catapulted Hoover into the public eye and made his name synonymous with law enforcement until he died in 1972 at the age of 77.

[citation needed] The capture of Karpis essentially ended the age of the big-name Depression Era criminal.

In addition to those mentioned earlier, others killed violently in the 1930s included Jack "Legs" Diamond, Vincent "Maddog" Coll, Frank "Jelly" Nash and Dutch Schultz.

But as the case was called for trial, "Thomas J. Newman, attorney for Karpis, told the court his client, one of the actual kidnappers of Hamm, desired to plead guilty.

[14] Sentenced to life imprisonment, Karpis was incarcerated at the then recently constructed Alcatraz federal penitentiary from August 1936 to April 1962.

Karpis wrote about Manson in his autobiography with Robert Livesey (1980): This kid approaches me to request music lessons.

Karpis was released on parole in 1969 and deported to Canada, although he initially had difficulty obtaining Canadian passport credentials, having had his fingerprints removed by underworld physician Joseph Moran in 1934.

In Edmonton, Alberta, while shuffling Karpis between various interviews with the media, M&S book representative Ruth Bertelsen stopped at her bank.