A 46-year-old Montana man pleads guilty in federal court Thursday to threatening to murder U.S. Sen. Jon Tester; He is Kevin Patrick Smith of Kalispell.

Smith faces a maximum of 10 years in prison and a $250,000 fine after admitting to threatening Tester’s life in voice messages left at the Democratic lawmaker’s office. 

Prosecutors said Smith made the threats because he was upset with Tester’s political decisions.

In late January, Smith made numerous phone calls to Tester’s office, including one in which he challenged Tester to contact the FBI, according to court documents.