Omaha Police Chief Alex Hayes provided no details on the weapon Butler used or how he obtained it. Butler’s father is a detective for the Omaha Police Department. Investigators were interviewing the seven-year veteran on Jan. 5 to learn more about what may have led to the shooting.

Authorities first received reports of the shooting around 12:50 p.m. The school was immediately locked down.

Sophomore Jessica Liberator said she was in the cafeteria when another administrator “rushed in to tell everybody to get in the back of the kitchen.”

She said she started to cry when students heard a knock on the kitchen door and a cafeteria worker yelled for everybody to get down. It was a false alarm. Nobody came in.

Within two hours of the shooting, students were being released in groups, and when the first group emerged from the school, parents began applauding. Some students smiled, raised their hands in the air and flashed a V for victory sign.

John Manna, who lives two blocks from the school, called Assistant Principal Kaspar a wonderful person who had worked as a counselor and teacher before becoming an administrator. Manna said he knew Kaspar because his older son graduated from high school with her son in 1996.

“I was just shocked. I can’t think of a nicer person. I can’t see how anyone would be cross with her,” Manna said of Kaspar before her death.

The school on the west side of Omaha has about 2,100 students. District officials said Millard South would be closed on Jan. 6.