This week, the cops arrested a 49-year-old Maine man and a 60-year-old Department of Education employee for planning crimes inspired by James Holmes, the 24-year-old Aurora shooter. Now Maryland police say they've arrested 28-year-old Neil Prescott, who calls himself "the Joker," for threatening his former boss by saying, "I'm gonna load my guns [of which he has 20] and blow everybody up." There was also a little something about his "brains splatter[ing] all over the sidewalk." And perhaps the most worrying detail of all: When the police arrived at Prescott's apartment to arrest him, Prescott answered the door wearing a T-shirt bearing the slogan, "Guns don't kill people. I do."