When you walk into the federal "supermax" -- or supermaximum security -- prison just outside Florence, Colorado, there are bright artificial lights, no windows, thick concrete walls everywhere ...

Larry Hoover, a cofounder of a notorious Chicago street gang who was imprisoned in a “supermax” prison for decades, has had his sentence commuted by President Donald Trump.

Guard towers loom over the administrative maximum security federal prison called Supermax near Florence in this 2007 file photo. Supermax prison, also known as ADX for "administrative maximum," is ...