A former University of Southern Maine student is facing federal charges for allegedly sending e-mail threats to two National Public Radio hosts.

John Crosby, 38, was arrested in late January by FBI agents and indicted late last month in U.S. District Court in Portland. Crosby lives in Cape Elizabeth and graduated from USM in 2009, according to the documents.

He was arrested inside the USM library and agents found a shotgun and shells in his Volvo station wagon, according to court records.

According to an FBI affidavit, Crosby sent a series of threatening messages to NPR hosts Melissa Block and Guy Raz.

A Jan. 17 message said Block “is helping to destroy me to use me as a human sacrifice. She will be raped, beaten, tortured, and murdered very soon,” according to the affadavit. That e-mail was traced to the Starbucks on Congress Street in Portland, it said.

Because the e-mails crossed state lines, Crosby is charged with transmitting threatening communications in interstate commerce, it says. He is being held in Cumberland County Jail.