Michael Disch will face a sentence of up to eight years as part of a plea agreement. Disch has been charged with mailing threatening communications, USA Today reports.
The 2009 letter, which was addressed to Judge Larry McKinney, was opened at the Terre Haute courthouse before reaching the judge. The powdery substance inside was later found to be benign.
Investigators do not yet know why Disch targeted McKinney, but Disch had complained about the conditions at the prison and had previously sent letters to the judge. Disch is currently an inmate at the federal prison in Lewisburg, Pa.
The letter contained both powder and instructions along with a threat to smell the contents of the package and die. The letter also threatened to find out where McKinney lived and to have his family killed, the Tribune-Star reports.
“Our message is a consistent and strong one,” Joseph H. Hogsett, the U.S. attorney for the Southern District of Indiana, said, according to the Tribune-Star . “We are committed to protecting the inmates from each other, and the safety of those who work there, and we take seriously threats made against authorities.”