BREAKING: ’Unabomber’ Ted Kaczynski, 81, found dead in prison cell

Ted Kaczynski, also known as the Unabomber, was found dead in his prison cell at the age of 81, according to a Federal Bureau of Prisons spokesperson. MSNBC national security analyst Clint Watts talks about how Kaczynski’s conviction and sentencing for a series of nationwide bombings that killed three people was an early instance of investigating domestic terrorism in the United States.  » Subscribe to MSNBC: Follow MSNBC Show Blogs MaddowBlog: ReidOut Blog: MSNBC delivers breaking news, in-depth analysis of politics headlines, as well as commentary and informed perspectives. Find video clips and segments from The Rachel Maddow Show, Morning Joe, The Beat with Ari Melber, Deadline: White House, The ReidOut, All In, Last Word, 11th Hour, and Alex Wagner who brings her breadth of reporting experience to MSNBC primetime. Watch “Alex Wagner Tonight” Tuesday through Friday at 9pm