Travis Butler is a junkie involved in a flash-mob robbery, which also involved a rape by one of the other participants, Jay Watson.
After Travis was caught on camera at the scene, Travis gets called in for questioning about his affiliation with Natalie's rapist. Travis denies knowing Natalie's rapist but doesn't deny being at the scene. Travis then gets released on bail. After a flash-mob attacks the SVU precinct, Travis is arrested at the scene and brought in for questioning, where he finally admits to knowing Natalie's rapist and gives up his name. (SVU: "Truth Embargo")