Birthright

S6, E1: Patty Branson (Abigail Breslin), 6, is attacked at the park while her father reads the paper. Benson (Mariska Hargitay) and Stabler (Christopher Meloni) believe a teenage boy attempted to molest her, but it turns out the boy (who's really a young man), and a middle-aged man, were following her. The pair are P.I.'s and they'd been hired by Michele Osborne (Lea Thompson) to kidnap Patty, who claims she is her daughter. Michele's story is strange - she said her husband took her daughter (who she named Anna) on a car trip, and was snatched from a rest stop. He subsequently died in a car accident. Sarah (Camilla Scott) and Matt Branson (Beau Gravitte) are horrified by the whole situation, claiming Patty is their daughter.