Dylann Roof, the Charleston shooter who killed nine members of a black church in 2015 in an act of white supremacist violence, staged a hunger strike while in federal prison.

Roof, 25, is being held on death row in Terre Haute, Indiana, and alleges that the prison’s staff is targeting him for abuse.

In a letter sent by Roof to the Associated Press on Feb. 13, the mass murderer claims that he has been physically and verbally assaulted by staff “without cause” and “treated disproportionately harsh.” He further claims that the staff feels they can get away with it because he is “hated by the general public.”

Roof’s hunger strike has ceased as of this week, a source told the Associated Press. It is still unknown how long the strike has lasted and its conditions.

“I feel confident I could have gone much, much longer without food,” Roof said in a second letter on Feb. 16. “It’s just not worth being murdered over.”

In his first letter, Roof suggested that he had been on a hunger strike for at least a few days. In the second, he claimed to stop after staff tried to hook him up to an IV, presumably to force-feed him nutrients.

Prison officials have not commented.

In January, Roof attempted to appeal his death sentence, as he claims that he was suffering from schizophrenia while on trial. Roof is the first person to be sentenced to death for a federal hate crime.

Dylann Roof Dylann Roof is seen in a handout booking photo provided by Charleston County Sheriff's Office, June 18, 2015. Photo: Getty Images/ Grace Beahm-Pool