A Blue Alert was issued on Wednesday for a man accused of shooting an Alvarado police officer during an attack at a U.S. Immigration and Customs Enforcement detention facility on July 4, according to the Texas Department of Public Safety and the FBI.

The suspect, a former U.S. Marine Corps reservist, is accused of joining 11 others in an organized attack against officers at the Prairieland Detention Center.

The suspect is believed to have fired two AR-15-style rifles at three officers, and his criminal complaint document says he was in the U.S. Marine Corps Reserves for five years.