Hours before he opened fire on two principals at his high school, a Nebraska teenager calmly accepted a suspension for driving on an athletic field. He went home to speak with his father and some friends -- all the while giving no hint of turning violent, police said Thursday.
But after his father left to run errands, Robert Butler Jr., 17, took a handgun from a closet and headed back to the school to confront the administrator who had punished him, police said.
Butler, whose father is a detective for the Omaha Police Department, asked to see the assistant principal and fatally shot her in her office with his father's service weapon. He then wounded the principal and fled before killing himself.
Authorities on Thursday outlined the events that led up to the shooting Wednesday at Millard South High School on the first day of class after the holiday break.
Butler had transferred to Omaha in the fall from a school in Lincoln, about 50 miles away. On New Year's Day, he was cited for criminal trespassing after driving his car on the school's football field and track, police said.
Butler was called out of class at 8:10 a.m. Wednesday to meet with Assistant Principal Vicki Kaspar. The two talked in her office, and he was escorted out of the school at 9:23 a.m., police said.
Butler stayed calm after learning of the suspension. "He wasn't acting like an out-of-control student at all," Police Chief Alex Hayes said. The teen got a ride home, where he talked with his father and spoke with some friends by phone.
Butler's father had no reason to expect that his son would turn violent because the teen did not seem distraught about the suspension and had no history of mental illness.
The father, who normally works an evening shift, left the home for about 40 minutes to run errands, Butler took his father's handgun out of a closet, posted an ominous message on Facebook predicting he would do "evil things" and broke into a locked garage where his father had stored his car since the trespassing incident.
Butler returned to the school at 12:45 p.m. but did not seem upset and even took the time to sign in at the office, asking to see Kaspar again.
Police said Butler had been in Kaspar's office about four minutes with the door closed before he shot her. He then walked across a hallway and shot Principal Curtis Case.