Law & Order: Special Victims Unit (1999) : 7x3

Benson is on her way out for the evening when a call comes in from a little girl who says she's all alone. While trying to draw the girl out, Benson is drawn deeper into the little girl's life, and although the other officers begin to suspect the whole thing may be some sick joke, Benson is convinced that the little girl is the real deal. By talking to Maria, Benson is able to ferret enough information from her so that they have a place to start, but Maria's captor has an affinity for electronics and has done everything he can to make sure that no one can find the little girl he bought and paid for.