NEWPORT NEWS, Va. (AP) — A criminal investigation into staff members at a Virginia school where a 6-year-old shot his teacher will continue, prosecutors said Thursday, one day after a former assistant principal was charged with felony child neglect.

“We’ll work with the school system to try to ferret out how this happened,” Newport News Commonwealth’s Attorney Howard Gwynn said at a news conference. “And based on the facts of the law, if we believe somebody else needs to be charged, trust me when I tell you, they will be charged.”

Ebony Parker was charged in indictments unsealed Tuesday following a special grand jury report that said she showed a “shocking” lack of response to multiple warnings the boy had a gun in the hours before he shot teacher Abby Zwerner in her first grade classroom.

Gwynn said the grand jury is no longer empaneled. But his office will continue investigating school officials in the January 2023 shooting at Richneck Elementary.

“The lapses in security were appalling and should never have happened,” Gwynn said. “And I think anybody who read that report had the same reaction: How could this happen?”

The probe in Newport News is among a small number of recent criminal investigations in the U.S. that are signaling a shift toward greater accountability of adults — teachers, parents and police — when it comes to preventing school violence.

“In tragic school shootings, civil lawsuits are very common, whereas criminal charges have been much more rare — although this is changing,” said Amanda Nickerson, a school psychology professor at the University at Buffalo.

Nickerson, whose research focuses on preventing school violence, said caregivers are facing greater scrutiny for how they respond to possible threats.

“Although each case is unique, what seems to make the difference in criminal cases are when the warning signs for violence are clear and prevention could have stopped the injury or death,” Nickerson said.

The mother of the 6-year-old who shot Zwerner was convicted in two separate cases. Deja Taylor got two years in prison for felony child neglect. She also received 21 months in federal prison for using marijuana while owning a gun, which is illegal under U.S. law.

Parker, the former assistant principal, faces up to five years in prison for each of the eight counts of felony child neglect filed against her. Parker posted a $4,000 bond Wednesday and attended a court hearing Thursday morning to discuss who her attorney would be. But the matter was continued until next month.

Parker did not comment to reporters and ran from cameras outside the courthouse.

The grand jury said Parker disregarded various concerns the day of the shooting, including several reports from teachers and students about the boy possibly having a gun. The report also itemizes missed opportunities to provide more resources to the often-misbehaving student, as well as tools Parker could have used to remove him from class in the months before the shooting.

The report also identifies a series of unaddressed security issues at the school, including a front door buzzer system that was not fixed for “weeks on end,” resulting in “no security as to who comes and goes in and out of the school.”

“The lack of oversight and care by key administrative staff in charge of Richneck regarding the obvious lack of security could have brought on unspeakable tragedy just because no one cared enough to ensure a safe learning environment for the students,” the report states.

In recent years, a handful of criminal investigations have focused on school employees. But they’ve had mixed outcomes.

For example, a former school resource officer in Florida was acquitted last year of all charges, including felony child neglect, after he was accused of hiding during the Parkland high school massacre in 2018.

Prosecutors in Uvalde, Texas, are still investigating the law enforcement response to the 2022 elementary school shooting, which is one of the deadliest in U.S. history. A grand jury was summoned earlier this year.

Police officials have been criticized for waiting far too long to confront the gunman, who killed 19 children and two staff members. The school system’s police chief was fired three months after the tragedy.

In 2021, a prosecutor in suburban Detroit criticized Oxford High School’s decision to keep teenager Ethan Crumbley in school before he killed four students. But more than two years later, the probe ended without charges of school employees in Oakland County, Michigan.

“We did not find sufficient evidence to support criminal charges,” David Williams, chief assistant prosecutor, said last month.

A school counselor and an administrator had met with Crumbley’s parents to discuss a violent drawing he made. They did not demand that the boy be taken home but the Crumbleys didn’t volunteer to remove him either.

No one checked his backpack, which contained the gun he used.

Like the mother of the 6-year-old shooter, the Crumbleys have faced condemnation for their roles in their son’s actions.

James and Jennifer Crumbley were sentenced Tuesday in Michigan to at least 10 years in prison.

The Crumbleys were accused of not securing their son’s newly purchased gun at home and acting indifferently to signs of his deteriorating mental health. They are the first parents convicted in a U.S. mass school shooting.

While national statistics are hard to come by, at least seven criminal cases against parents have been filed in the last eight years after a child brought a gun to school and it was fired, intentionally or not.