Federal investigators revealed that a California man has been indicted for mailing threatening messages, including to Pastor Robert Jeffress, who the man threatened to kill "in the name of Allah."

Jeffress is pastor of First Baptist Church Dallas, but is perhaps best known for being an outspoken supporter of President Donald Trump.

What are the details?

According to The Dallas Morning News, 32-year-old Darnell Ray Owens mailed a letter to First Baptist Church Dallas last year threatening to assassinate Jeffress.

"I will assassinate your pastor in the name of Allah," the letter reportedly said. "I will burn down Christian churches ... this is a threat."

An employee at the church opened the letter, which also contained an unknown white powder substance. Emergency officials quarantined the employee, later discovering the substance was nontoxic. The incident forced the church to take additional security precautions because the church was preparing for children's vacation Bible school at the time, the Morning News reported.

However, federal investigators say Jeffress' was not Owens' sole target. In fact, Owens is accused of mailing at least 45 similar letters, including to police departments, LGBT groups, and Christian groups.

A grand jury returned a seven-count indictment against Owens last week on charges of threat or hoax involving a biological weapon and identity theft, which investigators charged him with for using fraudulent return addresses on his letters, according to the Sacramento Bee.

Owens faces five years in federal prison for each count involving a threat or hoax and two years in prison for each count of identity theft.