Alcatraz Federal Penitentiary and the island became a prison of the Federal Bureau of Prisons in August 1934 after the buildings were modernized to meet the requirements of a top-notch security prison. Given this high security and the location of Alcatraz in the cold waters and strong currents of San Francisco Bay, the prison operators believed Alcatraz to be escape-proof and America's strongest prison. Alcatraz was designed to hold prisoners who continuously caused trouble at other federal prisons. One of the world's most notorious and best known prisons over the years, Alcatraz housed some 1,576 of America's most ruthless criminals including Al Capone,
Alcatraz Federal Penitentiary Prisons. The purpose of this transfer was to punish those involved in the rampant crime which prevailed in the country in the 1920s and 1930s. The United States Disciplinary Barracks on Alcatraz was acquired by the United States Department of Justice on October 12, 1933, and the island became a Federal Bureau of Prisons federal prison in August 1934. The $260,000 conversion to the federal prison took place from January 1934. George Hess of the United States Public Health Service was appointed the chief medical officer of the prison and Edward W. Twitchell became a consultant in psychiatry for Alcatraz