CHATTANOOGA (AP) — A federal grand jury has indicted a man on charges of threatening Republican U.S. Rep. Diane Black, who is running for governor of Tennessee.

The indictment against Clifton Ward was filed June 26 in U.S. District Court in Chattanooga. It says Ward threatened to assault and kill Black.

Black told Fox News that the man left her voicemails, and that his arrest makes her family feel better. She said she couldn't discuss details of the calls.

The news outlet reports the threats allegedly came after Black introduced a measure that would allow public donations to be used to build a wall between the U.S. and Mexico.

Black is in a hotly contested race for governor of Tennessee. The primary is Aug. 2.

Federal court documents did not list an attorney for Ward.