Infamously known as The Unabomber; he orchestrated a mailbomb campaign against universities and airliners for 20 years.
He was a mathematics genius and held a professorship at the University of California before becoming a misanthropic recluse.
The FBI named the case for the acronyms UN(inversity) and Airline BOM(bing), which is how Kaczynski got his nickname.
He was eventually exposed by his estranged brother.
For a time he was imprisoned in the same unit as the Oklahoma City bomber, Timothy McVeigh, and the two spoke; Kaczynski was unimpressed by the younger bomber.