NBC Chicago reached out to the Bureau of Prisons, which oversees ADX Florence, for comment. We have not heard back at the time of publishing. Hoover, 74, had been a federal inmate since 1998.

NBC Chicago reached out to the Bureau of Prisons, which oversees ADX Florence, for comment. We have not heard back at the time of publishing. Hoover, 74, had been a federal inmate since 1998.

“Mr. Hoover, who is now 75 years old, spent nearly 30 years in solitary confinement at ADX Florence — the most restrictive, draconian supermax prison in the United States,” his attorneys noted.