The shooting took place on the first day of classes Monday as several hundred students were in the cafeteria, where the sound of gunfire initially seemed like just another piece of the aural landscape. Students said it sounded like the pop of air that escapes when a bag of chips is opened, or the clap of a door slamming shut.
Instead, it was gunfire, striking a 17-year-old student who was airlifted to Maryland Shock Trauma Center as classmates and strangers offered prayers for him at impromptu gatherings and across social media. Police said they do not believe the victim, who was not identified, was targeted by the shooter.
Witnesses said a school counselor quickly grabbed the shooter and pinned him up against a vending machine. Police also declined to identify the 15-year-old suspect, who was taken into custody shortly after the 10:45 a.m. shooting, until they decide whether to charge him as a juvenile or an adult.
"He's in custody, our investigators are talking to him, he's cooperating, but he's not been formally charged yet," said Elise Armacost, a Baltimore County police spokeswoman, who noted that juveniles' records are not public. "Is he going to be charged as a juvenile, or is he going to be charged as an adult? I don't know the answer to those questions yet."
Police said they cannot confirm information appearing on various social media networks. Several parents and students pointed to a Facebook posting by someone who said he attended Perry Hall High and spoke of the first day of school being the last day of his life.
A man who identified himself as the suspect's father told the Associated Press that his son had been bullied but declined to give further details. A woman who said she was related to the father gave the following statement on the family's behalf: "We are horrified. We did not see this coming and our thoughts and prayers are with the victim and the victim's family."
Students described a day that suddenly turned chaotic during an early lunch break in the cafeteria of the school, the county's largest with nearly 2,200 students. Rather than the festive atmosphere of a school community returning after summer break, police helicopters whirred overhead, students dove under cafeteria tables and, as the news spread quickly, distraught parents tried to reach their children, in person or by phone or text message.
Throughout the day, a sense of disbelief pervaded.
Jeremy Knavel, 16, said he couldn't believe his eyes when he saw a student emerge from a bathroom Monday morning, taking a gun out from under his shirt.
"I thought it was a joke," he said. "Then when I heard the shot, I ran. I'm shaken still. I can't believe it actually happened."
Sophomore Nick DiPaula, 15, said he and a friend were talking in the cafeteria when they heard a loud bang and turned to see what it was.
"We just see him with the gun, and he's aiming it at my table," DiPaula said.
A school counselor he identified as Jesse Wasmer ran over and tackled the gunman as he and other students hit the floor and another teacher started yelling, "Get out of the building, get out of the building!" DiPaula said.
Wasmer was hailed as a hero by colleagues and across the Internet, where a "Thanks Mr. Wasmer" Facebook page was created. He could not be reached to comment, and school officials declined to discuss details of the incident.
The actions of Wasmer and other teachers in the cafeteria who intervened "were really beyond what anyone can be expected to do," and "made that situation the best it could have been in such a horrible time," said Matt Smoot, a science teacher in his fifth year at the school.
Dennis Sullivan, the school's lacrosse coach until last year, whose son Aidan is a senior at the school, said he knows Wasmer well and was not surprised by his actions. "He's definitely a hero in my book. He saved a lot of people's lives today with what he did," Sullivan said Monday night.
New Baltimore County schools Superintendent Dallas Dance, on his first day of classes after being hired this spring to head the school district, praised the school's "heroic, brave faculty."
Dance said Perry Hall High will be open Tuesday with additional security at the school. The Police Department's Critical Incident Stress Debriefing team will provide support for students and faculty, Armacost said.
Students and parents alike were unnerved by the incident, saying the school has always been considered safe.
It was "overwhelming," said Julia Schoennagel, 14, a freshman. "It was my first day, and I was excited to meet my teachers and see who was in my classes," she said. "It was unreal, I couldn't believe it. You never think that would happen at your school."
"I was scared to death," said her mother, Jeanne Schoennagel, who heard about the shooting and knew it was at the same time that Julia had her lunch period. "I don't want her ever to go back."
Junior Ryan Brady, 15, said he was several feet away from the shooting victim and saw blood on his shirt. As the counselor was tackling the shooter, his gun went off again, the bullet hitting the ceiling, said Brady, who got under a table to hide.
"After I got outside, my hands were shaking really bad," he said. "First thing I did was call my mom and told her everything that happened, and told her I was all right."
Police officers were already at the school, standard procedure for the first day of classes. County Executive Kevin Kamenetz said police and school officials responded in "terrific fashion" to the shooting.
"Obviously it's a difficult world we live in today, and I kind of hoped that Baltimore County would be immune from this type of activity," Kamenetz said. "But apparently we're not."
The shooting prompted swift reaction from elected officials, including Gov. Martin O'Malley, who said he had spoken with Kamenetz about the incident. "It takes all of us working together to make our schools safer for our children," O'Malley said.
Students were escorted to the nearby Perry Hall Shopping Center at the corner of Ebenezer and Belair roads, where parents were instructed to meet them, police said. Hundreds of visibly shaken parents and others gathered at the shopping center as police helicopters hovered overhead.
Students like DiPaula were able to text or call parents, siblings and friends. At least initially, incomplete information led to some confused and frightening moments.
"He pointed it at me but I'm OK," DiPaula texted his father, John DiPaula, who was at work and had no idea what his son meant.
A co-worker told the elder DiPaula about the shooting, which sent him into a panic because then he couldn't reach his son. Nick DiPaula told him later that he was unable to text or call again because teachers were taking away students' cellphones.
"I thought that was the most ridiculous thing," John DiPaula said. "He's afraid to call me because they're going to take his phone away? I mean, when is it appropriate to use your phone in school? Can you think of any better time than today?"
Nick DiPaula's sister, senior Julianna DiPaula, was in English class when a vice principal's voice came over the loudspeaker and said, "Code red, code red, we're under lockdown," she said.
At first she and her classmates thought it was a drill, she said, but then students started getting text messages saying there had been a shooting in the cafeteria.
"Then it hit me. Oh, my God, my brother is in that lunch," said the 17-year-old.
More than an hour later, Julianna and Nick were able to leave the school and meet their father in a nearby parking lot. When she saw her brother, Julianna ran to him, she said. "As soon as I saw him, I just started crying and hugging him," she said.
Miranda Wienecke, a junior, said she saw the suspect with a "huge black thing" that she soon realized was a gun.
"I saw people getting under the table," Wienecke said. "Then I saw people running. We heard this huge boom, then there was another one, everything happened very fast."
Senior Arielle Brown said students were in the cafeteria for about 15 minutes when they heard a pop, a sound she compared to the opening of a bag of chips. She and Wienecke said Wasmer and another teacher intervened, putting the shooter in a bear hug and pinning him against a nearby vending machine.
Senior Mike Koogle, who was down the hall, said, "We thought it was someone slamming a door. Then people started yelling. A teacher ran in and said, 'lockdown.' "
"We are kids. We were terrified," Koogle said. He said they went into a classroom, turned out the lights and did their best to hide.
With the school on lockdown immediately after the shooting, some parents who had rushed to Perry Hall were unable to reach their children.
"Why aren't all the kids out? Why is my daughter not allowed out?" said Jennifer Short, who lives around the corner from the school.
She called the phone of her daughter, Taylor Trayband, a senior, and burst into tears when she answered. "Oh, my gosh, my baby." Still on the phone, Trayband eventually walked up Ebenezer Road, and Short ran to her and hugged her.
By early afternoon, some students were still being released from the school. One group quietly walked arm-in-arm toward Perry Hall Middle School.
Baltimore County Councilman David Marks, who lives next door to Perry Hall High School, said he received dozens of phone calls shortly after the shooting from worried parents and residents.
"It's horrifying," said Marks, a graduate of the school. "This is a very peaceful community, and my prayers are with anyone who's been impacted by this."
Former Baltimore County state Del. Alfred Redmer Jr. called the incident "tragic" and a reminder that "this can happen anywhere. We all need to be diligent."
But Redmer said the shooting doesn't mean there should be more gun control. "When disturbed people do unconscionable acts, the weapon that they use really is irrelevant, whether it's a stabbing or a gun or a baseball bat," he said.
One parent wondered how a student got a gun without his parents knowing about it.
"How does he have a gun? How do his parents not know he is this far gone?" said Lisa Eisenmann, who has two children at Perry Hall. "Somebody's baby was hit. Somebody's child is in Shock Trauma fighting for his life."
U.S. Education Secretary Arne Duncan was at the school last Wednesday to address 800 Baltimore County English teachers to boost morale.
"My thoughts are with the Perry Hall High School community — students, families and faculty — in this difficult time," Duncan said in a statement Monday. "Gun violence has no place anywhere, least of all in our nation's schools. I'd like to thank the local educators and law enforcement personnel who took action to help prevent additional students from getting hurt."
Baltimore County Police Chief Jim Johnson is scheduled to provide an update on the investigation Tuesday morning. Kamenetz and Dance are expected to attend.
While the suspect is a juvenile, anyone over 14 years old can be charged as an adult if the crime is one that, if committed by an adult, is punishable by life imprisonment or death.
While the shooter's motives are unknown, problems that generally move students to violence aren't always focused on until there is a tragedy, said Lisa Hurka Covington, founder and executive director of an advocacy group called SPEAK, or Suicide Prevention Education Awareness for Kids.
She said some schools, including Perry Hall, have offered programs in the past to help students cope with bullying, suicidal thoughts, acts of violence, depression and other issues that have led some to harm themselves and others.
"We're losing too many young people," said Covington, who lost a sister to suicide before founding her organization. "We need them to know there is help."
Baltimore Sun reporters Liz Bowie, Meredith Cohn, Ian Duncan, John Fritze, Mary Gail Hare and Alison Knezevich contributed to this article.
Past school violence
Among other incidents of violence in area schools:
Nov. 21, 2008: A 15-year-old student was stabbed and killed outside Lemmel Middle School in West Baltimore. A 14-year-old classmate was arrested and ultimately convicted for the murder.
Oct 21, 2004: A 10th-grader and his older brother were shot outside Thurgood Marshall High School in East Baltimore. Three teens were convicted in the shooting, which left the brothers with non-life-threatening injuries.
May 7, 2004: Four students were injured, including one who was paralyzed below the waist, after two men fired into a crowd after a charity basketball game at Randallstown High School in northwest Baltimore County. The shooters and the man who supplied them with the weapon were convicted on a range of assault and handgun violations.
Sept. 20, 2001: A 17-year-old student was shot outside Lake Clifton-Eastern High School in Baltimore City. A 16-year-old who didn't attend the school was arrested in the case, which police characterized as a neighborhood dispute.
Jan. 17, 2001: A 17-year-old student was shot and killed on the grounds of Lake Clifton-Eastern High School as students were entering the building at the start of the school day. A 20-year-old man who was said to have had a dispute with the victim was convicted of the murder.