How we cite our quotes: All quotations are from The Departed.
Quote #1
DIGNAM: So you have family connections down in Southie, right? Through your father? Why don't you tell us about your Uncle Jackie?
Dignam knows all about Billy's Uncle Jackie, who was a big-time mobster in the tough neighborhood of Southie. But rather than hesitating at this, Dignam hopes he can use this to help insert Billy as a believable police informant.
Quote #2
DIGNAM: You got quite the family tree. That maggot uncle of yours... Tommy Costigan is another goof. He gets busted selling guns.
Yup, it looks like Billy's uncle Tommy was caught selling guns. In fact, it seems like it's hard to find anyone in his family apart from his dad who isn't (or wasn't) a career criminal.
Quote #3
DIGNAM: Family's all criminals except for the old man, huh?
The short answer to this question is yes. All members of Billy's family on his father's side are criminals except for his dad. This is in pretty stark contrast to Billy's mom's family, which seems made up of a bunch of rich New Englanders—whom Billy hates.