After the completion of its shootin time Harry gives you the Eye for an Eye quest. He tells you that hes tracked down Robson’s boyfriend Ian in Briar Valley and asks you not to use this information.
You tell him you need revenge and then he tells you he left Ians window open and that the easiest way to deal with him is to walk up to Ians house in Briar Valley and shoot him through the window.
Do as he asks, travel to Briar Valley, find Ians house and gun him down. Once you have done that report back to Harry.