Man pleads guilty to cyberstalking, threatening Okla. Rep. Kevin Hern

An Oklahoma man admitted Wednesday to cyberstalking Rep. Kevin Hern, R-Okla., and threatening Hern and his wife, federal prosecutors announced.

Keith Charles Eisenberger, 39, of Bartlesville, pleaded guilty to three federal charges, including cyberstalking; threatening to kidnap and assault a member of Congress; and threatening to kidnap and assault the spouse of a member of Congress, the Justice Department said in a statement.

He was first charged in May.

"The U.S. Attorney’s Office and our law enforcement partners will not tolerate online threats of violence meant to intimidate elected officials or members of our community. Keith Eisenberger now understands there are legal repercussions to committing these criminal acts," said U.S. Attorney Clint Johnson.

MORE: Man charged with threatening Oklahoma US Rep. Kevin Hern

According to the Justice Department, Eisenberger admitted to prosecutors that he threatened and harassed Hern online from Nov. 27, 2018, to May 11, 2022, and ultimately threatened to assault and kidnap Hern to interfere with his official duties. He later threatened to kidnap and assault Hern's wife.

Prosecutors said the concerning comments started in 2018 when Hern first assumed office and became increasingly violent as time went on. The threats were made during visits to Hern's office in Washington and over the phone and social media.

During one visit to Hern's office in 2019, Eisenberger told Capitol Police that he was angry because he thought Hern had been appointed to the seat without Eisenberger being considered for it, prosecutors said.

In a plea agreement, prosecutors and an attorney for Eisenberger agreed that sentencing guidelines call for 36 months in prison, the Justice Department said. He will then undergo 36 months of supervised release, according to the agreement.

Eisenberger's guilty plea comes at a time of what law enforcement has called heightened concern over political violence.

MORE: Armed man arrested for threat to kill Justice Kavanaugh

A Seattle man was recently charged with felony stalking after allegedly yelling racial epithets outside the home of Rep. Pramila Jayapal, D-Wash.

Another man was arrested in June for allegedly threatening to kill Brett Kavanaugh while outside the Supreme Court justice's home.

And in Ohio on Thursday, a suspected "domestic violent extremist" was fatally shot after attempting to break into an FBI office there, leading to an hours-long standoff.

Man pleads guilty to cyberstalking, threatening Okla. Rep. Kevin Hern originally appeared on abcnews.go.com