This too. And what's odd is that I hear people who say "Oh, in prison, they're safe from society." That's not true historically. Some of the most dangerous people in history were imprisoned, multiple times, and not killed for fear of public anger - only to get out of prison and wreak havoc.
Hitler was found guilty of treason, but was given a more humane 5 years in prison instead of the death penalty that would have historically been applied to treasonous people. He wrote Mein Kampf, got out of prison, started World War II, and killed millions.
Stalin was exiled to Siberia multiple times for his crimes including bank robbery, kidnappings, and extortion instead of being given death. He came back to Russia for the February Revolution, overthrew the Russian empire, started the Gulag system, and caused the deaths of millions.
For all we know, the Unabomber is in prison right now, but what happens if he escaped? It is not historically impossible, or even implausible, that he couldn't repeat history like many revolutionaries who were arrested, got out, and took over.
There is zero guarantee historically that people in prison are 100% totally safely isolated from society and can't do harm in the future.