WEST NYACK, N.Y. (CBSNewYork) — A teacher’s aide was found with a loaded gun on school grounds in West Nyack, police said.

It happened Wednesday morning at the Jesse J. Kaplan School on Parrott Road – a Rockland BOCES school for developmentally challenged students.

Clarkstown Police said they got a 911 call around 9 a.m. saying the 9mm Ruger was inside the teacher aide’s handbag, which was in a closet in a classroom.

A school resource officer secured the weapon “and ensured there were no further concerns for student’s safety,” police said.

A lockdown was initiated. There were no students inside the classroom at the time, many were on buses on their way to school.

“We diverted all the buses to a secure location so we could hold our children away from the building while we were in lockdown,” BOCES Chief Operating Officer Mary Jean Marisco said.

“The principal and the SRO were able to secure the firearm and deem it safe,” said Clarkstown Police Public Information Officer Peter Walker. “At that point, the determination was made to release the lockdown.”

Gillian Jeffords, of Warwick, was arrested and charged with criminal possession of a weapon on school grounds, a felony. When CBS2 cameras approached her residence, she claimed she had nothing to say.

Police say they’re looking for an explanation as well.

Jeffords, 24, has a full-carry firearms permit in New York and Pennsylvania, but police say the minute she walked on to school property she committed a felony.

“It’s against the law in New York state to possess or carry a firearm on school grounds unless you are a sworn police officer,” Walker said.

The licenses have since been confiscated and will be reviewed by a judge.

“We take the safety and security not just of our students but also of our staff and everyone in our school very, very seriously,” said BOCES District Superintendant Charlene Jordan.

Roxanne Rodriguez told CBS2’s Hazel Sanchez that she couldn’t be more relieved to leave the school with her 5-year-old son Maximus safe by her side Wednesday.

“This morning, it was pretty scary, because they shut down. And you know, anytime you see cops around the school or anything like that now you freak out. With everything that’s going on, it’s unfortunate to worry about the one place you feel your child should be safe,” she said.

Police said Jeffords never displayed the gun or made any threats, so investigators don’t know why she brought the weapon to school.

“To our knowledge, there was nothing alarming that had ever been mentioned about this individual and about her working in the district with the students,” Rockland BOCES communication director Scott Salotto said.

“I’m looking at it as a possible mistake, but that again is something we are trying to investigate it a little bit more,” a detective added.

Rodriguez said there’s simply no excuse to bring a deadly weapon into an environment filled with disabled students.

“God forbid somebody got in that bag. And I don’t think that was very responsible of her. So that’s not somebody that should be taking care of children with special needs,” she said.

Meanwhile, a neighbor who didn’t wish to be identified says she believes Jeffords may not have realized what she was doing was wrong.

“She would never break the law,” the neighbor said.

The school district says Jeffords was recently hired back in September. She’s now suspended without pay and is due back in court in May.