Perry Hall High School will maintain a heightened police presence until its principal determines that the campus is ready to return to normal, in the aftermath of a cafeteria shooting in which one student critically injured another on the first day of school.

Two days after the incident, schools spokesman Charles Herndon said county officials are “debriefing and evaluating” but have not decided on whether to permanently beef up security or student counseling.

“Right now, our attention primarily has been focused on the day-to-day recovery from this incident,” he said. “We’re focused on meeting the needs of students and staff at Perry Hall High School.”

Robert Gladden Jr., 15, accused of the shooting, remained held for treatment after undergoing a mental health evaluation. Victim Daniel Borowy, 17, who family friends said has Down syndrome, remained hospitalized Thursday morning in critical condition after being hit with a blast from a 34-inch-long shotgun. He is expected to survive.

Baltimore County schools Superintendent Dallas Dance visited Borowy on Wednesday. He said officials are reviewing Gladden’s records, but they are not aware of any information that would indicate a violent threat.

As the school system plots its course back to normality, experts say Perry Hall should focus on providing support to troubled students and steer clear of more visible trappings of security like metal detectors and ID card systems.

Katherine S. Newman, dean of Johns Hopkins University’s Zanvyl Krieger School of Arts and Sciences, said school officials need make it easier for kids who hear warnings about their peers to come forward.

“There’s lots of reasons why they don’t,” said Newman, co-author of “Rampage: The Social Roots of School Shootings”

After past shootings, some school systems have resorted to using identification cards, which Newman said will not stop student shooters. She said zero tolerance policies for minor infractions can drive students off campus and make their behavior less visible to teachers.

But Dr. James McGee, the retired director of psychology and forensic services at Sheppard Pratt Hospital and former chief psychologist of the Baltimore County Police Department, said it’s difficult for teachers to make judgments about students before a violent attack.

“As a group, they don’t have the instincts,” he said. Law enforcement officers tend to be more suspicious, he said, and, “more willing to acknowledge the dark side of humanity.”

“That doesn’t fit with someone who goes into education,” McGee said. “We’re looking for trouble. … They are just the opposite.”

School resource officers, police who have since 1997 been attached to Baltimore County schools, can provide students with an opportunity to share concerns with somebody outside of the school administration. That makes them incredibly valuable, Newman said.

Parents will have their chance to raise concerns at a meeting at the school Sept. 4, and the school board will hold a previously scheduled meeting at Perry Hall the same night.

Mary Lehnhoff, a close friend of Borowy’s family, urged parents to take time to talk with their children and learn about their aspirations and any problems they are facing.

“Just see what’s in their heart and mind and what’s going on in their life,” she said.

Herndon, the schools spokesman, said the shooting is a reminder for all the members of the school community to be on the alert for students who might be facing emotional or personal difficulties. But he declined to comment specifically on what school counselors might have done to help Robert Gladden.

“I would remind everybody that this was the very first day of school,” Herndon said. “I don’t want to particularly characterize what may or may not have happened.”

Baltimore County State’s Attorney Scott D. Shellenberger said Gladden, who has been charged as an adult with attempted murder, had a scheduled bail hearing delayed because he remains at a medical facility.