The New York City Department of Education has been sanctioned for not preserving a surveillance video that could have provided evidence in a lawsuit filed by the mother of a student who was slashed while leaving school for a field trip.

Manhattan Supreme Court Justice Margaret Chan ruled Thursday in Rodriguez v. City of New York, 114739/10, that the jury will be given an adverse instruction about the missing video.

In the same ruling, Chan denied the education department’s motion for dismissal or summary judgment, rejecting its argument that the mother was required to plead that the school had a “special duty” to her son.

The student, Pascasio Rodriguez, was attacked outside the Henry Street School in lower Manhattan in April 2010. He was walking toward the subway at the back of a group of students for a field trip when several young men, not students at the school, attacked him, slashing his face. According to Anthony Iadevaia, an attorney who represents Rodriguez and his mother, the attack left Rodriguez with a visible scar across his entire face and neck.

Rodriguez testified that there were two teachers with the group, both of whom were at the front looking at cameras or phones at the time of the attack. A dean who was acting as a chaperone, Stephanie Hasandras, testified that there were also five chaperones, but could only confirm that she and two others were present during the assault.

Rodriguez’s mother, Maria Rodriguez, sued the education department and the city, alleging inadequate supervision and negligent hiring, training and retention.

In September 2011, Hasandras testified during her deposition that she had seen video from a surveillance camera outside the school taken at the time of the incident, and Rodriguez’s mother immediately asked that the department produce the tape. The court issued several orders that the education department comply with the request; the last of those orders, in October 2012, said that if it did not comply within 45 days, it would be precluded from offering any evidence as to liability at trial. Shortly before that deadline, the agency submitted a response saying the video had been taped over.

Rodriguez’s mother moved for sanctions for spoliation of evidence.

Chan said in Thursday’s order that “the cavalier attitude of defendants and their failure to preserve a video that depicted at least some of the activity involved in this litigation is troubling.”

“It is particularly concerning that the video was not preserved where a police investigation immediately ensued, a notice of claim was filed on June 17, 2010, for this civil action, and the faculty of the school thought to view the video soon after the events occurred and, in the case of Dean Hasandras, prior to her deposition,” the judge said.

A sanction, in the form of an adverse jury instruction, was therefore appropriate, she concluded.

Chan also addressed the defendants’ motion to dismiss or, alternatively, for summary judgment. She ruled that the city was improperly named as a defendant, and that the suit would go forward only against the education department. She also dismissed the negligent hiring, training and retention claim, finding that any school employees responsible were acting in their professional capacity and the claim was therefore precluded by the doctrine of respondeat superior.

Chan ruled that the inadequate supervision claim could go forward. The Department of Education had argued that it should be dismissed because Rodriguez’s mother failed to plead that it had a “special duty” to her son.

Chan said, however, that under “well-settled law,” the department has “an unqualified and mandatory duty to supervise the activities of the students in its charge,” quoting a 1993 First Department decision, Shante D. v. City of New York, 190 AD2d 356, 361.

She also rejected the agency’s argument that the school could not be liable because the attack was not foreseeable. Whether it was foreseeable was an issue of fact for a jury, she ruled.

Iadeveda said he was not surprised with the decision on spoliation, since he had asked for the surveillance video “immediately” and the department waited until right before a court-imposed deadline to respond.

“They didn’t put any real defense to the spoliation issue,” he said.

He said that, while he would have preferred a stronger sanction than an adverse jury instruction, he was pleased with the decision.

Iadevaia also said the city was “relying on the wrong type of doctrine” in its summary judgment motion. “They relied on special duty, but … as soon as you hand a kid over to the school, he becomes their responsibility,” he said.

The Department of Education was represented by Robin Shin, an attorney with the New York City Law Department, which declined comment.