A Hawaii man is facing federal charges after allegedly threatening to kill Michigan Governor Gretchen Whitmer.

Investigators say 48-year-old Ronald Saville sent threatening emails to Michigan State Police and Governor Whitmer in May, claiming he planned to carry out a mass shooting at the state capitol. Authorities say he was arrested in Texas on June 1 after admitting he wanted to assassinate Whitmer because of her political views and had researched traveling to Michigan.

Saville has previous convictions for threatening former President George W. Bush and a federal judge. He faces up to five years in prison on each count.