Prosecutors have added a terrorism-support count against a 21-year-old man Border Patrol arrested in Mission, Texas, after he crossed the Rio Grande between ports of entry on July 10.

Jose Flores Flores first faced only an unlawful-reentry charge because of earlier immigration arrests. A later indictment accuses him of aiding the Gulf Cartel, one of seven Mexican trafficking groups the United States has designated a foreign terrorist organization.

The filing says he watched police, served as an armed member, and helped conceal corpses for the group in Mexico, without stating his rank or further specifics.