A US-born man is in custody on a 48-hour U.S. Immigration and Customs Enforcement hold at the Leon County Jail in Tallahassee, Florida, after he was charged as an “unauthorized alien” who entered Florida without being inspected by immigration officers,

Juan Carlos Gomez-Lopez is being held even though a county judge found his birth certificate “authentic” and said there wasn’t reason to consider him an “illegal alien.”

The authorities identified the attacker as a 20-year-old student at the university, and said he appeared to have been acting alone.

Multiple victims were reported in a shooting Thursday at Florida State University and a suspect was taken into police custody, a person familiar with the matter told The Associated Press. The extent of the victims’ injuries was not immediately known and there were no additional details about the person who was in custody.