Malcolm Wolinsky is a member of the Association for the Protection of Children vigilante group, trailing the moves of the Special Victims Unit in the investigation into the disappearance and murder of Henry Morton by following police scanners.
Wolinsky personally followed suspect and convicted pedophile Billy Turner to his apartment, accosted him, and ransacked his apartment to intimidate Henry's whereabouts out of Turner. Turner was later revealed to be innocent, and when Wolinsky organized rioters after Turner's release, he was arrested.
It was later discovered he arrived at the house of the real killer, teenager Jake O'Hara, pretending to be a detective to get information for the unofficial search. When this was revealed by Jake's account, Wolinsky was additionally charged with impersonating an officer of the law and later imprisoned. (SVU: "Conscience")