OMAHA, Neb. -- The son of a police detective opened fire at a Nebraska high school Wednesday, killing the assistant principal and forcing panicked students to take cover in the kitchen of the building just as they returned from holiday break.
The gunman, who had attended the school for no more than two months, also wounded the principal before fleeing from the scene and fatally shooting himself in his car about a mile away.
Authorities declined to speculate about why the suspect, identified as 17-year-old Robert Butler Jr., targeted the administrators.
Vice Principal Vicki Kaspar, 58, died at a hospital hours after the shooting, police said. Principal Curtis Case, 45, was listed in stable condition.
Jessica Liberator, a sophomore at Millard South High School, 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.
She huddled with Brittany Brase, another sophomore. Asked whether they were best friends, Brase said, "No, not really." But, she added: "She's my best friend now. These things bring you together."
Butler had transferred in November from a high school in Lincoln, about 50 miles southwest of Omaha.
In a rambling Facebook post filled with expletives, Butler warned Wednesday that people would hear about the "evil" things he did and said the school drove him to violence.
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."
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 said he remembered 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.
Butler's stepgrandfather, Robert Uribe, said the news still seemed unreal to him Wednesday evening and didn't seem to fit with the polite teen he knew.
"I have no idea what led to this," said Uribe, who last saw Butler about a month ago. Uribe said nothing appeared to be wrong at that time.
Lincoln school officials declined to provide details about Butler's student record. But Lincoln Southwest High School Principal Rob Slauson said Butler was involved in few, if any, activities before transferring to the new school.
"I think it's safe to say that in the yearbook, there was one picture of Robert Butler, and that was his school picture," Slauson said.
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 Wednesday 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, but within two hours, students were being released in groups.
When the first group of students emerged, parents began applauding. Some of the students smiled, raised their hands in the air and flashed a V for victory sign.
Crystal Losole, whose son and a nephew are juniors at the school, said she got a call from her son when he was hiding in the kitchen.
Hugging him later and weeping, Losole said when she learned of the shooting, "My knees kind of buckled."
Her son, Skyler Marion, said he was in the cafeteria when Assistant Principal Brad Millard loudly announced that there was "a code red" and that everybody needed to evacuate.
At first, nobody believed Millard, Skyler said. But when Millard's face turned white, students knew it was no joke.
John Manna, who lives two blocks from the school, said he knows 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.
The shooting news jolted the suburban neighborhood in west Omaha where the principal lives.
"I'm really sad," said Judy Robison, who lives six houses away from the Case family. "There's been shootings downtown, but we're really pretty insulated out here."
The school on the west side of Omaha has about 2,100 students.