Doug (last name unrevealed) is a frat brother at Phi Delta in Westmore College in on a conspiracy with Gregory Engels and Lizzie Harmon to bring attention to finding Greg's missing brother Jason.
Discussing the plan on burner phones, Greg then sets up numerous sites with graffiti and equipment before they recording Lizzie's "rape" at knifepoint by Doug in a ski mask. Streaming it to the entire college while bouncing between servers, the three send the police on a chase to find the site spray painted with the three wise monkeys, eventually leading to the brownstone of the Engles' foster parents.
Doug's seen at the frat house when the detectives ask about his tattoo in Chinese calligraphy. To make it harder for the police, every frat brother has the tattoo. Doug's later seen with Lizzie "held hostage" tied to a bed, hitting her and holding the knife to her throat. Greg's eventually tracked and arrested, but with Lizzie still missing, Special Victims set out to find Jason. He's rescued from his captor, Miriam Penner, and Greg keeps his word of revealing Lizzie's location.
Police burst into an apartment where Doug sits next to Lizzie, who's unharmed other than a shiner as part of the act. Greg says he'll take all the blame so Doug and Lizzie can get off before they're led out. It's never specified if Doug was charged or the deal was made with the prosecutor. (SVU: "Spectacle")