A Maryland man pleaded guilty Thursday to lying to federal investigators in connection to death threats he sent to a member of Congress.

Sidhartha Kumar Mathur, 35, of West Friendship admitted making a threatening phone call and sending a threatening message through the Maryland congressman’s website.

“I will kill you and blow up your office if you try to take my vote away” and “I know where you and your family lives,” Mathur wrote in the messages sent through the website, according to his guilty plea.

Soon after, court records show he left a threatening message on the congressman’s office voice mail in which he said, “If you even mess with my vote, I’m going to come and slit your throat and I’ll kill your family.”

Court records identify the targeted congressman as being from Maryland but do not name the specific member. A spokesperson for the U.S. attorney’s office for Maryland cited its general policy of not identifying crime victims.

Mathur was arrested in December. During an interview with U.S. Capitol Police agents, he confirmed the phone number used to leave the threatening voice mail was his and said he called the lawmaker out of anger. But he falsely denied writing the threatening message that used similar language, according to the plea agreement.

Mathur’s attorneys did not immediately respond to a request for comment Thursday.

Mathur will be sentenced on Sept. 9 and faces a maximum prison term of five years.