CARBONDALE, Ill. (AP) — A Southern Illinois man has pleaded guilty to claiming in a letter that he’d planted a bomb at an area school and threatening letters to local government officials, according to a published report.

Citing court documents, the Southern Illinoisan reported that Jonathan Wade Bohn pleaded guilty in federal court last week to charges of mailing threatening communications and interstate threat to use destructive devices. He was sentenced to one year and one day in prison and will begin serving that sentence when he completes his sentence on a bank robbery charge on July 26, according to court records.

The charges stem from 2014, when Bohn mailed letters from a federal prison in Pennsylvania where he was serving time for 2010 bank robbery, first to the Franklin County State’s Attorney’s Office and then two weeks later to the county’s circuit clerk.

In the first letter, he threatened violence against county officials and law enforcement officers. Two weeks later, in a letter to a county clerk he claimed that there was a bomb inside a school in the county that was set to detonate the next day — prompting officials to temporarily close nine schools in the county.