A federal judge entered a plea of not guilty Monday on behalf of Jared Lee Loughner to three counts of attempted murder in the mass shooting that wounded U.S. Rep. Gabrielle Giffords earlier this month.

After entering the packed courtroom, Loughner, 22, showed the same smirk as he had in his mug shot. He appeared to chuckle to himself as he looked into an upper balcony area filled with spectators. He smiled occasionally during the 15-minute arraignment and remained silent.

U.S. District Court Judge Larry Burns asked federal public defender Judy Clarke about Loughner’s ability to comprehend the proceedings.

“We are not raising that issue at this time,” Clarke told the judge.

When the judge asked for plea from the defendant, Clarke asked the judge to enter one on Loughner’s behalf.

Loughner is charged with trying to kill Giffords and two of her aides, Ron Barber and Pamela Simon.

Prosecutors have turned over hours of videos taken off Loughner’s home computer to the defense. They also provided the defense with witness statements, attorneys said in court. Clarke acknowledged she received two discs from the prosecution.

The next court hearing is scheduled for March 9 and is expected to be held in Tucson, not Phoenix, at the request of prosecutors, who wanted to be closer to witnesses and victims. The defense said it had no problem with the request as long as his attorney knows where Loughner will be held in Tucson.

Monday’s arraignment was held in Phoenix because the mass shooting occurred in Tucson, in which six persons were killed and 13 more were wounded. Among those killed was Arizona’s chief federal judge, John Roll of Tucson, and all federal judges in Arizona then recused themselves from Loughner’s proceedings.

Monday’s hearing was presided over by Burns, who’s from the U.S. District Court for Southern California, based in San Diego. He was designated to head the case by the 9th Circuit Court.

Prosecutors said they might file a superseding indictment within the next 30 to 45 days.

Legal experts expect additional charges, including those for the murders of six people, to be filed against Loughner, who is a Tucson resident.

Meanwhile, in Houston, Giffords continued to show improvement in her rehabilitation from a gunshot wound to the head.

Despite reaching a series of milestones, Giffords has a long road ahead, doctors have said. Once she enters rehabilitation, the process is expected to take four to six months.

(Source: CNN)