“I don’t know what would possess him to do that,” Uribe said.

Assistant Principal Vicki Kaspar, 58, died at Creighton University Medical Center the evening of Jan. 5, hours after the shooting. Principal Curtis Case, 45, was in serious but stable condition.

Butler posted a rambling message on Facebook shortly before the shooting about his unhappiness with his new school, but he didn’t supply many details. Instead, the expletive-laced note predicted Butler’s friends would hear about the “evil things” he was about to do.

He wrote that the Omaha school was worse than his previous one, and that the new city had changed him. He apologized and said he wanted people to remember him for who he was before affecting “the lives of the families I ruined.” The post ended with “goodbye.”

Butler had transferred in the fall from a high school in Lincoln, about 50 miles southwest of Omaha. A former classmate of Butler’s from Lincoln confirmed the Facebook post to The Associated Press and provided AP with a copy of it.

Conner Gerner recalled Butler as being energetic, fun, and outgoing. Gerner said Butler sometimes got in trouble for speaking out too much in class, but he did not seem angry.