Administrators at the Virginia school where a child shot his teacher learned the youngster may have had a weapon in his possession before the shooting – but did not seize the handgun he brought to his classroom, the school system’s superintendent said.

George Parker told parents on Thursday night in an online meeting that a school official was notified about the weapon before the six-year-old shot the teacher at Richneck Elementary in Newport News.

“At least one administrator was notified of a possible weapon in the timeline that we’re reviewing and was aware that that student had, there was a potential that there was a weapon on campus,” the superintendent told parents, according to a clip of the meeting broadcast by WAVY-TV.

The online meeting was for parents only, but WAVY-TV reported the station gained access to the meeting from a parent.

The superintendent and a school spokeswoman did not respond to multiple messages from The Associated Press. Details about how they learned about the weapon and why it was not found before the shooting were not immediately available.

The police chief has previously said the boy brought the gun to school in his backpack.

The teacher, Abigail Zwerner, 25, was shot in the chest with injuries initially considered to be life-threatening. Her condition has improved, though, and she has been reported to be in a stable condition at a hospital.

Earlier on Thursday, Newport News School Board chair Lisa Surles-Law said the district will install metal detectors at all schools, starting with Richneck.

The January 6 shooting occurred as Ms Zwerner was teaching her class. Authorities said there was no warning and no struggle before the six-year-old boy pointed the gun at Ms Zwerner.

Police chief Steve Drew has described the shooting as intentional. A judge will determine what’s next for the child, who is being held at a medical facility following an emergency custody order.

Mr Drew said the child used his mother’s gun, which had been purchased legally. It is unclear how he gained access to the weapon. A Virginia law prohibits leaving a loaded gun where it is accessible to a child under 14 as a misdemeanour.