WASHINGTON - Federal law-enforcement officials have recovered "reams of videotape" from surveillance cameras at the Safeway shopping center where U.S. Rep. Gabrielle Giffords was shot, video that they said leaves no doubt about how the gunman methodically went about killing six people and wounding 13 others.

The video, from multiple cameras posted around the grocery store parking lot, is "very, very clear," one federal official said.

"It's so clear, you can even tell the sequence of who got shot when and where," the official said. "And it's not the grainy kind of typical fast-food or mini-mart robbery tape. It is so clear it leaves no issue about who was doing the shooting."

As an example, one official who has had the video described to him in detail that it shows that Giffords was shot first, followed by U.S. District Judge John M. Roll, who was standing near Giffords. Roll, 63, Arizona's senior federal judge, was killed in the rampage.