WASHINGTON – A federal grand jury in Arizona has indicted accused Tucson gunman Jared Lee Loughner on 49 counts in the January rampage that wounded Rep. Gabrielle Giffords and 12 others and left six dead, including a chief federal district judge.

Employing a novel legal argument, the superseding indictment adds 46 additional federal charges to the case against Loughner on the theory that the crime at the Safeway where Giffords was meeting with constituents occurred on protected federal ground, as if it happened inside Congress.

Loughner was initially indicted in Phoenix on three federal counts of attempted murder against the Democratic congresswoman and two of her aides, all of whom were considered federal officials who were performing federal duties when they were shot.

The new indictment adds charges for the killing and wounding of victims who are not federal employees. It also adds charges for attendees at the event who were not injured.

Loughner, 22, faces the death penalty if convicted. He will be arraigned on the new charges Wednesday inside the same federal district courthouse in Tucson where the deceased judge, John Roll, presided.