The gang began robbing banks starting in mid-1931, but on December 19 of that year, they killed Howell County Sheriff Calvin Roy Kelly in West Plains, Missouri.
They used the name "Anderson", but a few weeks later, Helen's son Nick recognized Alvin's and Fred's photos in a copy of True Detective Magazine, and contacted the police.
St. Paul's corrupt chief of police, Thomas Brown, tipped the Barkers off and they left town.
Doc Barker later joined the gang in 1932 after he was paroled from the Oklahoma State Penitentiary in McAlester, where he had been serving a life sentence for the murder of night watchman Thomas J. Sherrill in 1921.
They then kidnapped Edward Bremer in daylight in St. Paul, Minnesota in January 1934, releasing him in February.
George "Shotgun" Ziegler had been gunned down in Cicero, Illinois in March 1934, possibly due to the mob's dislike of the gang's activities.
The arrest of Karpis brought the FBI to fame and skyrocketed their public standing, along with J. Edgar Hoover's reputation.
While at McNeil Island Penitentiary Karpis began to teach guitar to the young Charles Manson, then known as “Little Charlie”.
Karpis was sympathetic to Manson‘s tumultuous, institutionalized upbringing which saw him in countless orphanages, reformatories, and prisons all throughout his young life.
He died on August 30, 1979, of natural causes, though it was initially believed to be a suicide or the result of foul play.