Spree killings are rare, and yet 2012 witnessed a surge of them, from the Oikos University massacre in Oakland, Calif., to the Sikh temple killings in Oak Creek, Wis. Among them was the Aurora, Colo., shooting, one of the worst massacres since Columbine. Confusion and chaos reigned on July 20, when an early showing of the Batman movie "The Dark Knight Rises" turned deadly. The gunman fired rounds of bullets in the theater, killing 12 people and wounding 58. The criminal case against the suspect, James Holmes, is in a preliminary stage with no trial date set.