A Dallas school nurse is accused of stealing medication from students and replacing the medications with other drugs.
Rebecca Bailey-Long, a nurse at K.B. Polk Vanguard Elementary School, allegedly replaced Ritalin for one child with a similar-looking, potentially dangerous painkiller.
The Dallas Independent School District said one other student's medication was replaced with an over-the-counter medication.
Neither student was seriously harmed, DISD said.
Bailey-Long also worked at Townview Magnet Center, but the school district said it appears switches were only done to two students.
"The dispensing of medicine -- you have to ultimately trust a registered nurse, and that's what was taking place here, so how do you guard against it? That's something that we're going to try and work through it and try to figure out how to do that," said Dallas Independent School District spokesman Jon Dahlander.
The school discovered the Ritalin switch during a medication audit that was triggered when the child's mother inquired at the school because her child was acting oddly.
"The student wasn't acting what they felt was the right way after school, so that is what tipped off the parent," Dahlander said. "The parent told the principal, and we went from there."
The student's mother had delivered the bottle of Ritalin at the beginning of the year.
One pill was supposed to be given every day. Each pill was inscribed with the letter "M" on one side and the number "10" on the other. The painkiller found in the child's pill bottle was also inscribed with "M" on one side, but had "T7" on the other side.
Police said they found pill bottles, controlled substances and dangerous drugs in Bailey-Long's home during a search warrant.
Bailey-Long was arrested Friday and is facing criminal charges. She checked herself into a drug rehabilitation program as part of her bond conditions.
She is on paid administrative leave.