The boy filmed himself penetrating her from behind, her torso exposed, her head hanging down, prosecutors said. He later shared the cellphone video among friends, investigators said, and sent a text that said, “When your first time having sex was rape.”

But a family court judge said it wasn’t rape. Instead, he wondered aloud if it was sexual assault, defining rape as something reserved for an attack at gunpoint by strangers.

He also said the young man came from a good family, attended an excellent school, had terrific grades and was an Eagle scout. Prosecutors, the judge said, should have explained to the girl and her family that pressing charges would destroy the boy’s life.