An Arizona man has been indicted on charges of threatening to “blow the brains out” of Rep. Raúl Grijalva and his staff because of the Arizona Democrat’s opposition to the state’s new immigration law.

Justin M. Hayes, 31, is charged with threatening to assault, kidnap and murder officials or employees of the United States, according to a news release Monday from the Department of Justice.

“This office takes threats against any individual, including public officials, with the utmost seriousness,” Dennis Burke, U.S. attorney for the District of Arizona, said in the release. “This is not protected speech. Such crimes endanger the civility our democracy is built upon.”

Hayes, who is from Phoenix, allegedly called Grijalva’s Tucson office on April 23 and threatened to kill him. He faces a maximum of 10 years in prison, a $250,000 fine or both. His first court date is set for June 24 in the federal district court in Tucson.

Grijalva has spoken out repeatedly against the new state law — set to go into effect July 29 — that would make it illegal to be an undocumented immigrant in Arizona. Since the Republican-controlled legislature passed the law, Grijalva has called for national and regional groups to protest what he sees as racially motivated legislation by not holding conventions in Arizona.