A woman was arrested after allegedly posing as a teacher and attempting to kidnap a 4-year-old boy outside an elementary school in Vacaville on Thursday, police said.

Dispatchers first received reports of a woman displaying “erratic and concerning behavior” near Cooper Elementary School around 8 a.m., according to the Vacaville Police Department.

She was apparently photographing vehicles and individuals, and even tried to open the car door of a parent who was dropping off a child at the campus, police said in a statement.

A short time later, 56-year-old Aileen Caringal is accused of approaching a 4-year-old boy while his stepfather was dropping off an older sibling at the school, according to police.

She allegedly asked the boy if he was ready to go to school, then grabbed his hand and started leading him away from campus.

The stepfather saw this and questioned her. Caringal told him she was a teacher and that the boy — who she called “Brian” — was in his class, according to the police statement.

The parent became alarmed, as that was not the boy’s name, nor was he was a student at the school. It also turned out that Caringal does not teach there, police said.

Caringal allegedly tried to get away with the boy, but only made it some 15 feet before the parent intervened and freed him from her grasp, the statement read.

She followed the pair, insisting she was his teacher and threatening to call the police chief if she wasn’t allowed to take him, authorities said.

Another adult assisted by bringing the children to the school’s office while the stepfather waited for police.

Caringal then ran to her home nearby, where officers took her into custody.

She was arrested on suspicion of kidnapping and trespassing on a school campus while interfering with children, according to the statement.

Caringal is being held on $250,000 bail, inmate records showed.