A Texas mother and her 13-year-old son were taken into custody Monday after authorities said the child was found with ammunition, tactical gear and an improvised explosive device, which his mother allegedly purchased for him.

Ashley Pardo, 33, was arrested and charged with aiding in the commission of terrorism after her son, who had a known fascination with mass shootings, showed up to Rhodes Middle School in San Antonio on Monday wearing a mask and tactical gear, police said.

“We don’t know whether he was armed when he showed up at the school,” San Antonio Police Chief William McManus said at a press conference Thursday. “He may well have been, but we don’t know that now.”

The child left the school shortly after his arrival but was then arrested off campus, police said.

“The young man was apparently planning some act of violence based on the things that we found out he was doing,” McManus said while explaining the terrorism charge.

The boy had been on authorities’ radar since January, McManus said, after he was found to have drawn “disturbing images of his school and expressing a fascination with mass shootings.” At the time, police met with the child and his family, offering resources and services to them, McManus said.

Three months later, in April, the child was suspended after authorities said he was found researching mass shootings on a school computer. He attempted suicide on the same day of his suspension, McManus said.

The school increased its security when he returned from his suspension last week. A few days later, police said a family member said they saw him with tactical gear and hitting a live bullet with a hammer, which the boy said his mom bought for him. That family member contacted police the following day after allegedly finding loaded magazines and an improvised explosive device in the boy’s possession.

Pardo had repeatedly been contacted by police, the school and child protective services about her son’s disturbing behavior, which she appeared “dismissive and unconcerned” about, McManus said.

According to a copy of a court affidavit obtained by local station KSAT, Pardo allegedly bought the items “with knowledge” that they would be “used to plan and carry out” a crime.

“Her behavior is not only dangerous, it’s abhorrent, especially as a parent,” McManus said.

“Most attackers show warning signs: obsessive interest in past violence, graphic fantasies, weapons stockpiling or violent writings. These signs must be reported. That’s exactly what happened on Monday. Family members spoke up and within hours law enforcement responded, implemented safety plans and took action,” he continued.

The mother has been released on bond while her son remains in custody as of Thursday, pending a judge’s review. Attempts to reach Pardo for comment were not immediately successful.