WASHINGTON (NEXSTAR) — U.S. Representative Adam Kinzinger is expressing concern after his family received a death threat over the weekend.

He says it’s over his participation in the House Select Committee’s investigation of the Jan. 6 insurrection.

Kinzinger posted the letter to Twitter. He says it was mailed to his home and addressed to his wife. The person who wrote the letter threated to harm him, his wife and his 5-month-old child.

Kinzinger and Liz Cheney are the two republicans on the January Sixth Select Committee. According to The Hill, Kinzinger believes the Republican National Committee is encouraging threats against lawmakers.

“There is violence in the future, I’m going to tell you. And until we get a grip on telling people the truth, we can’t expect any differently,” Kinzinger said.

Kinzinger is not running for re-election.

To read The Hill’s full story, you can click here.