The San Diego County man found with an AR-15-style rifle after allegedly threatening a mass killing of Muslims at an Inland Empire mosque is facing federal charges, officials announced Friday.

Louis White, 60, of Warner Springs, was charged Thursday with mailing threatening communications to the Riverside County mosque, according to the U.S. Department of Justice.

According to court documents, on Aug. 26, the Islamic Center of Temecula Valley reported to law enforcement that it had received a threatening letter that read, in part, “I CANNOT WAIT FOR THE DAY TO KILL EVERY ONE OF YOU, IT CANNOT COME SOON ENOUGH!”

Under the text was a hand-drawn image of crosshairs containing a bearded face with X’s for eyes and wearing a hat, stating, “[expletive] Allah,” the DOJ said in a news release.

Investigators traced the letter to White and searched his home.

During a search of White’s residence on Aug. 29, law enforcement seized several firearms, including one believed to be an AR-15-style short-barreled rifle with no serial number, commonly referred to as a “ghost gun,” the DOJ said.

White was arrested and is currently in state custody at a Riverside County jail. He is expected to be transferred to federal custody in the coming weeks.

Read More:

If convicted, White would face a maximum sentence of five years in federal prison.

The Islamic Center of Temecula Valley is a local mosque and community organization serving Muslim residents in the Temecula and Murrieta area.