The gunman charged with capital murder in the mass shooting at a Walmart in El Paso has been placed on suicide watch, authorities said. Twenty-one-year-old Patrick Crusius was placed in a single cell under close watch Monday on the recommendation of medical staff at the county jail, according to the El Paso County Sheriff’s Office. Crusius is accused of killing 22 and injuring dozens more, and has allegedly confessed to officers, according to an arrest affidavit. Crusius said he was targeting Mexicans in the attack, and drove over 10 hours to El Paso from his home in suburban Dallas. The U.S. Attorney’s Office is also investigating the crime, and could potentially file federal hate-crime and domestic terrorism charges against Crusius, The El Paso Times reports. Crusius has been in custody without bond since Aug. 3.