An Army veteran threatened to shoot an Illinois congressman, over a widely debunked conspiracy theory about Ukraine's role in the 2016 U.S. election, prosecutors said Thursday.

Randall E. Tarr, a 64-year-old resident of Rochester, Illinois, has been charged with making a criminal threat, in a voice mail, against U.S. Rep. Rodney Davis (R-Ill.), according to the U.S. Attorney's Office out of Springfield.

SPRINGFIELD, Ill. (WAND) – A man from Rochester has been arrested after making threatening calls to U.S. Congressman Rodney Davis’ Decatur office. https://t.co/qbSWf1wHT3 — WAND TV News (@wandtvnews) December 12, 2019

The defendant claims he saw Davis in a political ad on TV, allegedly backing the widely debunked conspiracy that Ukraine was the real culprit of meddling in the 2016 presidential election — and not Russia. The U.S. intelligence community has agreed that Moscow meddled in the 2016 election, and not Ukraine.

Rep. Rodney Davis, R-Ill., speaks during the House Administration Committee hearing on Oversight of the Smithsonian Institute in Washington on Sept.18, 2019. Caroline Brehman / CQ-Roll Call, Inc via Getty Images file

Davis' spokeswoman, Ashley Phelps, said the congressman has not aired any recent TV ads. But he has been targeted by a veterans group that's critical of Trump and his foreign policy, according to his office.

Phelps said she doesn't recall her boss ever pushing the debunked Ukraine theory, that's a favorite talking point of President Donald Trump and some Republicans.

"Congressman Davis has consistently said Russia is responsible for meddling in the 2016 elections as the Mueller investigation found," Phelps said in a statement to NBC News on Friday.

But in an October interview with CNN, Davis appeared to be at least open to investigating whether or not Ukraine could be a 2016 interference culprit.

Davis said, "are you sure that Ukraine didn't have any role in the 2016 election interference?"

"That's something that I thought all of us, the Republicans and Democrats, wanted to look into," he then added.

Tarr called Davis' Decatur office on Nov. 25 and left a profanity-filled voicemail accusing the lawmaker of backing Russia, according to a criminal complaint.

"Man, I just saw you on TV. You back the Russians, boy?" Tarr said in his voicemail, according to criminal complaint. "What's wrong with you. Are you so f--cking stupid?"

In the message, Tarr said he was a sharpshooter.

"I was in the military for eight years and you son of a bitch are backing the Russians over our own intelligence? What is wrong with you Rodney?" Tarr said. "I'm a sharpshooter. I could. I'd like to shoot your f--cking head off you stupid motherf--ker."

Tarr, in an interview with The Associated Press, admitted to the call and said he was upset by a political ad on TV that purportedly showed Davis backing the widely debunked conspiracy theory about Ukraine.

Tarr said he regrets making the call and said he doesn't own a gun.

“I said I had been a sharpshooter in the Army. I didn’t realize I said anything about shooting him. I might have. I don’t even own a weapon,” Tarr told AP. “I wish I could just take it all back and just say he’s a lousy (expletive) for backing the Russian theory.”

If convicted, Tarr would spend up to 10 years behind bars. He was assigned a federal public defender on Thursday and released "from custody under conditions, including home detention and location monitoring," according to prosecutors.

Davis has won election four times in his central Illinois, 13th Congressional District. But his last election was razor thin, as he fended off Democrat Betsy Dirksen Londrigan by less than 1 percentage point.