A Fargo, N.D., man is accused in federal court of emailing threats to Sen. Heidi Heitkamp for nearly four years.

Kevin Lee Olson sent an email on Dec. 22, 2016, in which he threatened to shoot the senator in the head. Heitkamp had received threatening emails from Olson, 55, since 2014, the Pioneer Press reported. 

“It’s (sic) seems the only consideration these days is when one becomes a criminal. I guess I should find you, you (expletive), and shoot you in your red head!” the threatening email read in part. 

Olson was charged in U.S. Federal District Court of making threatening messages such as “I’m coming for you!! Now what will you hide behind?”

Olson was arrested for transmitting in interstate commerce communications containing a threat,” the U.S. Capitol Police told the newspaper. The agency also told the Pioneer Press it began investigating Olson last fall after he sent threatening messages to a member of Congress.

In April of last year, Olson filed a lawsuit against the U.S. Treasury Department and Social Security Administration asking for exemption from the Affordable Care Act.

Olson admitted to police that he sent the threatening email but refused to answer questions about the statements. He did state that he owned firearms.