(Newser) – Jared Lee Loughner pleaded not guilty today to dozens of new federal charges that accuse him of killing six people and wounding 13 others. Loughner, who smiled as he was led into the courtroom, entered the plea to charges that included trying to assassinate Rep. Gabrielle Giffords, attempting to kill two of her aides, and murdering federal judge John Roll and Giffords staffer Gabe Zimmerman.

He also is charged with causing the deaths of four others who weren't federal employees. Loughner appeared before US District Judge Larry Burns in khaki prison clothes, his once-shaved head now featuring short, dark hair and side burns. Loughner's father also was in the courtroom, and he listened to the proceedings with his arms crossed, head down, and eyes closed. (Read more Jared Lee Loughner stories.)

