Dear Mr. Metcalf,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located two series Notorious Offenders Files, 1919-1975 and Notorious Offenders Files, 1920-2010 in the Records of the Bureau of Prisons (Record Group 129) that both include records relating to inmates in various U.S. Penitentiaries, including Alcatraz Island. Some of these files have been digitized. For information about the non-digitized files, please contact the National Archives at College Park - Textual Reference (RDT2) via email at firstname.lastname@example.org.
The National Archives at San Francisco (RW-SB) also has inmate lists primarily dating from 1934 to 1963, however some may date back to 1910. You may find the list of former inmates online here, arranged both alphabetically by surname and numerically by register number. For access to these records, please email RW-SB at email@example.com.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RDT2 & RW-SB. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this is helpful. Best of luck with your research!