A charter elementary school on the Lower East Side is telling families they will be reported to the city’s child-welfare agency if they make a habit of not picking up their child on time.

The Girls Prep Charter School flier, posted on the education activism blog Ed Notes Online, says even one late pick-up could have consequences: If parents don’t arrive, students will be escorted by a staff member at the all-girls school to the local police precinct about a mile away. “Repeated failure to pick students up on time will result in a report to the Administration for Children Services,” the notice reads.

Dropping students off at the local precinct who have been left at school is city policy, noted Detective Jaime Hernandez, who heads community affairs at the Lower East Side’s Ninth Precinct. But the invocation of the city’s child welfare agency raised eyebrows among some parent advocates on Friday.

“You’re almost criminalizing parents. You’re calling them neglectful,” said Ocynthia Williams, an advocate with the Coalition for Educational Justice. “The bottom line is it’s a terrible policy for parent engagement at that school.”

Norm Scott, a retired teacher who manages the blog, said he received a picture of the notice from an anonymous emailer, and it’s unclear when the sign was posted. Asked about the sign and the school’s pick-up policies, Public Prep CEO Ian Rowe, who manages Girls Prep, didn’t respond to questions about the mention of ACS but said the school’s pick-up policies are rarely enforced. Only one student was picked up at the precinct last year, he said.

“We work closely with our parents when they face an expected or unexpected situation in which their daughter must be picked up after 3:45,” Rowe said in an email. “Our staff typically stay well after the end of the school day to ensure the safety of the student, until the parent arrives.”

The flier posted online was not visible outside Girls Prep on Friday, where another sign taped to the entrance doors noted that the school day had ended at 12:30 p.m. and offices closed by 1 p.m. That sign did not warn families that they would be reported to the city’s child welfare agency, but said that parents who arrive late to pick their child up should head to the police station.

But frequent late pick-ups alone aren’t likely to land a parent in trouble with the Administration for Children’s Services. A representative for City Hall deferred comment to that agency, whose spokesman said that school officials would actually be required to contact a division of the state’s Office of Children and Family Services, where the flier’s threat probably wouldn’t hold up under further scrutiny.

One former ACS official also said the warning was highly unusual.

“Parents being slightly—or even moderately—late at picking up their children after school doesn’t fit any definition of abuse or neglect in New York state,” said the former official. “I’d doubt the State Central Register would even accept the report made by the school, assuming it’s not just an idle threat, which it probably is.”

It’s not the first time that Girls Prep Charter School has caught heat for its unconventional approach to communicating with parents. Last year, the school hastily canceled a student-recruitment campaign that promised to pay families who brought in new students. The campaign, which offered $100 to parents if they brought in students who stayed for at least three months, drew criticism from charter school opponents and from supporters for challenging the notion that quality alone would attract parents to schools.