At the time of the Battle of Alcatraz, Thompson was serving life plus 99 years for murder of Texan police officer Detective Lemuel Dodd Savage, 52.

[2][3] Detective Savage was shot and killed while transporting Thompson and Elbert Day to jail.

[5] While in Alcatraz, Thompson was part of the Battle of Alcatraz, an escape attempt that ultimately left Correctional Officer Harold Stites and Correctional Officer William Miller, of the Federal Bureau of Prisons, dead from gunshot wounds.

Thompson was tried for his part in the violence, specifically accused of inciting Joe Cretzer to open fire on nine hostage guards in an effort to eliminate witnesses.

Thompson was found guilty along with inmate Sam Shockley, and they were executed simultaneously in the gas chamber of San Quentin on December 3, 1948.