Sonia Briglund is a grieving mother whose son Joey disappeared. She always suspected convicted pedophilic rapist Darren Tolson, following him everywhere and spreading flyers to warn people.
When a teenager named Riley Cuskey was murdered, with no identification on them, police at first assumed he was a street runaway or other high-risk or exploited child. A neighbor gave Tolson up, Tolson elading detectives to Sonia when he worried she set him up. Sonia was questioned, and when seeing Riley in the morgue, she mistakenly identified Riley as Joey.
Riley's identity was eventually revealed and confirmed, with the status of Sonia's son being left unknown. (SVU: "Pretend")