The 22-year-old Arizona man accused of shooting 20 people while trying to assassinate a U.S. congresswoman has made his first court appearance to face federal charges, Voice of America reported. Jared Loughner was in shackles Monday as he entered a Phoenix courtroom under heavy security. With his head shaved and wearing a prison uniform, he told the court he understood his rights. Loughner’s court appearance came two days after the mass shooting in Tucson that killed six people and left U.S. Representative Gabrielle Giffords of Arizona critically wounded. Thirteen others also were wounded.