FILE - In this June 21, 1996, file photo, Theodore Kaczynski looks around as U.S. marshals prepare to take him down steps at the federal courthouse to a waiting vehicle in Helena, Mont. In handwritten letters to hundreds of supporters and curiosity seekers, Kaczynski expressed shock over the 9/11 attacks and wrote that he preferred Hillary Clinton over Barack Obama in the 2008 Democratic presidential race. Kaczynski also wrote to pen pals from federal prison in Colorado asking for more information about Osama bin Laden and the origins of al-Qaida, and has relied on others to inform him about the rise of the Internet and social media. (AP Photo/Elaine Thompson, File)
  • Theordore Kaczynski
    FILE – In this June 21, 1996, file photo, Theodore Kaczynski looks around as U.S. marshals prepare to take him down steps at the federal courthouse to a waiting vehicle in Helena, Mont. In handwritten letters to hundreds of supporters and curiosity seekers, Kaczynski expressed shock over the 9/11 attacks and wrote that he preferred Hillary Clinton over Barack Obama in the 2008 Democratic presidential race. Kaczynski also wrote to pen pals from federal prison in Colorado asking for more information about Osama bin Laden and the origins of al-Qaida, and has relied on others to inform him about the rise of the Internet and social media. (AP Photo/Elaine Thompson, File)
  • Ted Kaczynski, unabomber
    FILE – In this April 4, 1996 file photo, Ted Kaczynski, also known as the Unabomber, is escorted into the federal courthouse in Helena, Mont. Harvard alumni attending their 50th class reunion are getting updates on classmates _ including Kaczynski, who graduated in 1962. In an alumni directory, he lists his occupation as “prisoner” and under awards lists “eight life sentences.”(AP Photo/Elaine Thompson, File)

DENVER  |  The man known as the “Unabomber” has been transferred to a federal prison medical facility in North Carolina after spending the past two decades in a federal Supermax prison in Colorado for a series of bombings targeting scientists.

Theodore Kaczynski, 79, has been moved to the U.S. Bureau of Prison’s FMC Butner medical center in eastern North Carolina, according to a bureau inmate database. The reason for his transfer was not provided.

He’s serving life without the possibility of parole following his 1996 arrest at the primitive cabin where Kaczynski was living in western Montana. He pleaded guilty to setting 16 explosions that killed three people and injured 23 others in various parts of the country between 1978 and 1995.

FMC Butner has 771 inmates, according to the prison bureau, and has been home to some notable offenders. They include John Hinckley Jr., who was evaluated there after shooting President Ronald Reagan, and Bernard Madoff, the infamous architect of a massive Ponzi scheme who died at the North Carolina facility earlier this year.

The deadly homemade bombs that Kaczynski sent by mail — including an altitude-triggered explosion that went off as planned on an American Airlines flight — changed the way Americans sent packages and boarded airplanes.

The Harvard-trained mathematician had railed against the effects of advanced technology and led authorities on the nation’s longest and costliest manhunt. The FBI dubbed him the Unabomber because his early targets seemed to be universities and airlines.

He forced The Washington Post in September 1995 to publish his anti-technology manifesto, “Industrial Society and Its Future.” The treatise led his brother David to recognize his writing and turn him in to the FBI.