Ted Kaczynski, known as the “Unabomber," died of suicide, AP reports

Theodore 'Ted' Kaczynski (in orange) is guided to his arraignment by federal marshals, Helena, Montana, April 4, 1996. He had been arrested in connection with the 'Unabomber' bombings and the deaths those explosions caused. (Michael Macor/The San Fra

Ted Kaczynski, known as the "Unabomber," who carried out a 17-year bombing campaign that killed three people and injured 23 others, died by suicide, four people familiar with the matter told The Associated Press.

Kaczynski, who was 81 and suffering from late-stage cancer, was found unresponsive in his cell at the Federal Medical Center in Butner, North Carolina around 12:30 a.m. on Saturday. Emergency responders performed CPR and revived him before he was transported to a hospital, where he was pronounced dead later Saturday morning, the people told the AP.

The people were not authorized to publicly discuss Kaczynski’s death and spoke to the AP on condition of anonymity.

Kaczynski’s death comes as the federal Bureau of Prisons has faced increased scrutiny in the last several years following the death of wealthy financier Jeffrey Epstein, who also died by suicide in a federal jail in 2019.

RELATED: Ted Kaczynski, the 'Unabomber,' dies in prison

Kaczynski had been held in the federal Supermax prison in Florence, Colorado, since May 1998, when he was sentenced to four life sentences plus 30 years for a campaign of terror that set universities nationwide on edge. He admitted committing 16 bombings from 1978 and 1995, permanently maiming several of his victims.

Balsamo reported from Miami.