Seth (surname unknown) is a serial assailant of homeless people at the behest of his girlfriend and accomplice Sara, when she hated vagrants after her father was killed by a homeless man and she wanted "revenge".
The two were the first suspects of the castration and burning of Josh Gatti, a homeless high school graduate with schizophrenia. John Munch lured the both of them out, pretending to be a vagrant, and both were arrested after assaulting him. They confessed but were cleared of Gatti's fatal attack, as Alec Bernardi acted off his sister, Tina, consenting to being pregnant with Gatti's baby in a school pregnancy pact.
Both were found guilty on multiple assault charges and imprisoned. (SVU: "Babes")