Ross Campo is a dirty cop working illegally as a private investigator and enforcer. He was hired by Saleh Amir to track his daughter, Nafeesa Amir, to the point of beating her boyfriend Daoud Tarzi for information. It didn't work in the end, and he became a suspect when Naseefa was found brutally murdered in a public park.
When detectives tracked him, they didn't sell him out to Internal Affairs, but he revealed his second employer was a third party liaison for Saleh, the the killer of Nafessa along with his son Jaleel Amir. (SVU: "Honor")