A sixth-grade teacher in Arizona has been arrested after the parents of a 13-year-old boy found text messages indicating a sexual relationship between the pair, police said.

Brittany Zamora, a 27-year-old teacher at Las Brisas Academy Elementary School in Goodyear, was taken into custody late Wednesday after the discovery of the text messages, which implied the pair had gotten physical both on and off campus, KPHO reports.

“The text messages found are sexual in nature [and] allege an ongoing relationship between the two,” said Lisa Kutis, a spokeswoman for the Goodyear Police Department.

The texts were found because the boy’s parents had installed an app to monitor his phone, Kutis said.

“As a result of the app, which alerted the parents to some key words, they then checked the cellphone and discovered these text messages,” Kutis told the station.

The boy’s parents then informed the school’s principal about the texts before the allegations were relayed to police, along with screenshots of the incriminating texts, according to Liberty School District interim district superintendent Richard Rundhaug.

“The safety of our students is our #1 priority,” Rundhaug said in a statement posted on the school’s website. “Transparency is equally important. We are fully cooperating with the Goodyear Police Department and will comment further at the appropriate time.”

Parents of students at the school learned of Zamora’s arrest via an automated message, KNXV reports.

“It just freaked me out right away,” Jessica Arroyo told the station. “That’s just crazy. I can’t even connect that. That’s wrong.”

It’s unclear whether other students may have been communicating with Zamora and detectives are conducting additional interviews, Kutis told the Arizona Republic.

“That’s part of our overall investigation,” Kutis said. “We’re not ruling that out.”

It’s unclear how long Zamora taught at the school, but she was certified in 2016 to teach elementary students in the state, according to online records.