Theodore John Kaczynski aka the "Unabomber" is a former mathematics professor, a domestic terrorist, and serial killer who between 1978 and 1995 killed 3 and wounded 23 others by attempting to start a nationwide combing campaign targeting people involved with modern technology. 
Kaczynski was found dead in his cell on June 10, 2023.
 
8” x 10” four page handwritten letter hand signed twice. The letter is hand dated January 26, 2015.
The Unabomber has hand signed the top of the first page, Ted Kaczynski, and initaled the tops of pages 2, 3,and 4 TJK. Hand signed at the close, Regards, Ted.Kaczynski has inserted a sheet of paper between the letter and the back of the envelope on which he writes a note to the mailroom.Includes the original prison mailed envelope with his complete return address postmarked February 3, 2015 and hand signed, Theodore John Kaczynski, with both his complete return address and the recipient's written by the Unabomber.