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. Two page handwritten letter hand signed twice. The letter is hand dated July 6, 2001, hand signed at the top of the first page, Ted Kaczynski, hand signed again at the close, Ted Kaczynski. Includes the original prison mailed envelope postmarked Colorado Springs, CO July 11, 2001. The envelope has been completely written by The Unabomber,  hand signed, Theodore John Kaczynski.