A trucker has been charged in federal court with threatening to kill President Donald Trump in numerous phone calls to Secret Service field offices.

Matthew Lariviere a Special Agent wrote in a criminal complaint unsealed Tuesday that James Anthony Jackson repetitively called the Secret Service field office in Chicago on Oct. 12-13 and made more phone calls on Oct. 18 to the field office in Detroit threatening to “blow Trump’s brains out.”

Jackson called from a phone that was registered to James Jackson Profit Group LLC in Grand Rapids, Michigan Lariviere wrote. The Detroit News reports the company is related to an outreach center in Grand Rapids.

The News reports that Jackson was born in 1984 but a birthplace wasn’t available. Therefore, the U.S. Attorney’s Office refused to discuss the case.