Guns don't kill people — people who use the assault rifles that the National Rifle Association lobbied Congress to un-ban in 2004 kill people.
UPDATE 4:45 P.M. ET: This was originally posted with an inaccurate shots-per-minute number and an image of the wrong gun. We've modified and corrected the graphic, with new facts sourced to this page and others.
The exact gun used in Aurora, Colorado was a slight variation on this: an AR-15-style weapon made by Smith and Wesson, with an after-market 100-round drum cartridge.
The stuff about the NRA and the assault weapons ban has always been true, and was not changed.