The parents of a 13-year-old boy are moving forward with an amended civil lawsuit against a special education school in Northfield, where they allege a female classmate sexually assaulted him.

In doing so, the parents have voluntarily dropped several claims of negligence, alleging harm to themselves and their daughter, and refocused the lawsuit on how they say the school wronged their son. They withdrew the earlier claims on the condition that they will not raise them in the future.

Their decision came after Spaulding Youth Center and other co-defendants – Auburn School District and its parent administrative unit, SAU 15 – filed motions to dismiss certain claims in U.S. District Court in Concord.

School officials say they could not have known that any alleged sexual harassment at Spaulding would lead the boy to act out at home and, further, engage in sexualized behaviors.

The boy’s parents reported finding their son after he had sexually assaulted his younger sister at their Auburn home. That incident prompted an investigation by the Division for Children, Youth and Families in fall 2015, and the family to request his educational records.

And only after that, the parents said, did they learn about the abuse the boy suffered while a student at Spaulding.

In January, the boy’s parents moved him to a residential facility in Massachusetts. Soon after, they filed their civil lawsuit in federal court.

The boy’s parents accuse Spaulding of failing to prevent the sexual abuse and the Auburn School District and SAU 15 of not properly monitoring his time there.

School officials “did not take appropriate steps to investigate the reported incidents, protect (the boy), or take appropriate actions to prevent future incidents and harm to (him),” according to the lawsuit.

Spaulding was founded in 1958 and now serves up to 70 students with varying disabilities, including neurological impairments and behavioral difficulties. The private, nonprofit center employs more than 180 people and reports a $10 million yearly operating budget. It is funded through a combination of state and federal funds, as well as payments from referring districts.

The boy began attending Spaulding in May 2013, as part of his individualized education plan.

He first reported the harassment to a counselor in March 2015, claiming a girl had rubbed her breasts in front of him and told him to suck on them, the lawsuit says. He said previously that she had grabbed his butt.

The boy later reported to another employee that the girl had breathed heavily down his neck as she walked by his seat.

School officials admitted that the boy spoke up several times about how he felt uncomfortable around the girl. He also communicated that he was afraid she would try to touch him. Staff told the boy they were “handling the situation” and encouraged him to report any future incidents.

Spaulding denies that it failed to communicate with the boy’s mother about the alleged harassment prior to October 2015, when she requested his educational records. She also requested a copy of the school’s policy on sexual harassment, which she said she never received.

Months after the boy was discharged from Spaulding, he told DCYF investigators that the girl had placed her hands down his pants and made him touch her breasts and genitals.

Spaulding said in its response to the federal lawsuit that its “highly improbable that such an incident actually occurred.” The school maintains that a staff member was always assigned to the female student and that, therefore, she never would have been alone with the boy.

U.S. District Court Judge Joseph Laplante recently ordered that “any communication between Spaulding, (the girl), or her parents about the incidents of harassment that form the basis of the complaint” be turned over to the court. That includes any documented behavioral issues, any disciplinary action taken as a result and any steps the school took to prevent future incidents, according to Laplante’s order.

The court has ordered that those records be shared with the boy’s parents no later than today.

The earliest projected trial date is October 2017.

(Alyssa Dandrea can be reached at 369-3319, adandrea@cmonitor.com or on Twitter @_ADandrea.)