At a press conference, the Sheriff indicated that it's likely that the shooter did not act alone:
Pima County Sheriff Clarence Dupnik said Saturday evening that the man linked to the shooting of Rep. Gabrielle Giffords and others might have an accomplice.
"We are not convinced he acted alone," Dupnik said at a news conference.
Dupnik said investigators have reason to believe the 22-year-old suspect whom he would not name came to the scene with someone else. "We have photos," Dupnik said of the gunman's companion.
Nate T. Gray, of the FBI, referred to bringing "those responsible" to justice.
