The ailing Native American rights activist has been in prison for nearly 50 years after the U.S. government lied to put him there.

President Joe Biden on Monday commuted the sentence of Leonard Peltier, a Native American activist convicted of killing two FBI agents nearly 50 years ago in South Dakota. Peltier, 80, is a citizen of the Turtle Mountain Band of Chippewa in North Dakota.

The president commuted Peltier over the objection of former FBI Director Christopher Wray. In a private letter sent to Biden earlier this month and obtained by The Associated Press, Wray reiterated his position that “Peltier is a remorseless killer,” and urged the president not to act.