The FBI had recorded the serial numbers of all the cash used to pay the ransom. They launched an intensive investigation, declaring Alvin Karpis, presumed leader of the gang, to be "
Public Enemy No. 1". Bremer, completely traumatized and worried about the safety of his wife and children, refused to cooperate with the FBI. When they threatened to reveal what they believed about his links to organized crime, he admitted what he knew about the kidnappers, and his suspicions about their connection to Sawyer. The gang knew that they needed to launder the money, but the intensity of the FBI pressure meant that most of their criminal contacts refused to participate. Ziegler was gunned down in a drive-by killing by unknown assailants in March. Sawyer claimed that he had arranged for the money to be laundered in Cuba. The gang withdrew to Cuba, but Karpis became concerned that the money had not been laundered and that the FBI would soon find them there. They moved to
Lake Weir, Florida. Doc left for Chicago, hoping to organize a new criminal project. He was soon recognized and arrested on January 8, 1935 along with minor gang member Byron Bolton. Doc wouldn't talk, but Bolton told the FBI everything he knew in exchange for a light sentence. Eight days later, Doc's brother
Fred Barker and mother
Kate "Ma" Barker were killed in a shootout with the FBI at Lake Weir. Volney Davis was also captured, and Sawyer was tracked down and captured in Mississippi.
Alvin Karpis, who was co-leader of the gang along with Fred Barker, was arrested by the FBI in May, 1936. Karpis pleaded guilty to kidnapping and Doc Barker was convicted after a trial. Both men were sent to
Alcatraz. Karpis became the Rock's longest serving inmate, eventually being paroled in 1969 after decades in prison. Barker was shot while trying to escape from Alcatraz in 1939. Sawyer received a life sentence in 1936. He was released from prison in 1955 due to ill health and died shortly after. ==Aftermath==