Opinion: It was recently reported that David Bain's groomsman was convictered killer Paul Wilson, who served 15 years for raping and murdering a former girlfriend in 1994, about a month before the Bain murders. Wilson stood beside Bain at the alter while he got married. The other two groomsmen were Karam's two sons, with Matthew acting as best man. Karam is quoted as saying: "They sort of naturally became ... very close friends. The single person he [Mr Bain] has spent the most time with over the past 18 years is Paul Wilson."
While it is understandable that Bain would befriend people while in jail and coincidentally they would be criminals, I would think that if you felt you didn't belong there, then that would be a reason not to establish deep friendships but also you would find that you were not able too identify with the other people because of the criminal choices they made. If such barriers did not exist for David, then he felt that he belonged there. Well we know he did.