Phoenix - Tucson shooting suspect Jared Lee Loughner pleaded not guilty on Monday to federal charges of attempting to assassinate US Representative Gabrielle Giffords and attempting to murder two of her staff members.
The 22-year-old college dropout is accused of opening fire on Giffords and a crowd of bystanders outside a grocery store on January 8, killing six people, including a federal judge, and wounding 13. Giffords was shot in the head but survived.
Wearing an orange prison jumpsuit and wire-rimmed glasses, the shaved hair on his head starting to grow back, Loughner said nothing as the not-guilty plea was entered on his behalf by the judge at his lawyer's request.
The shackled defendant was earlier seen smiling, nodding and chatting quietly with his attorney, Judy Clarke, as the proceedings were about to begin. She patted Loughner on the shoulder as the hearing ended.
Authorities have said Giffords, who remains hospitalised with a bullet wound to the head, was his primary target.
The shooting rampage renewed a national debate over gun control in the United States and whether the vitriolic tone of US politics might encourage violence against elected officials, though the motives for the attack remained unclear.
In the meantime, investigators for the FBI and the Pima County Sheriff's Department in Arizona are pressing ahead with parallel criminal investigations.
The plea of not guilty was entered for each of the three charges contained in a federal grand jury indictment returned last Wednesday - the attempted assassination of Giffords and attempted murder of two aides who also were struck by gunfire.
He could face up to life in prison for trying to kill the lawmaker and the other two attempted murder charges carry a maximum sentence of 20 years. - Reuters