“He just seemed like he had a lot of energy. He liked to talk to people. He was always moving,” Gerner said.

Another friend, Jacob Edward Rinke, said he and some others had exchanged Facebook posts with Butler the night before the shooting. The discussion was about cars and included what Rinke described as normal ribbing between friends.

“We were hazing each other about car stuff. He seemed fine and everything. He seemed happy,” Rinke said.

Rinke said Butler had lived up the street from him and they used to play sports and video games together.

“He didn’t seem like a kid who would go out and do this. When I first heard about this in school I didn’t believe it. I was pretty much in denial about it,” Rinke said.

Another acquaintance from Lincoln, 15-year-old Justin Reynolds, said he and his older brother used to hang out with Butler at a local skate park.

“He was always trying to make a joke,” Reynolds said. “No matter what mood someone was in, he was always trying to make them feel better.”

Lincoln school officials declined to provide details about Butler’s student record there, but they described him as a “fairly normal, average student.” Lincoln Southwest High School Principal Rob Slauson said Butler was involved in few, if any, activities.