My favorite line of all time comes from digmin.  "I'm the guy who does his job.  You must be the other guy!"

Billy sent the tapes to Dingnam also. Scorsese said it.

I like the detail of Dignam's oversized tracksuit, the understanding being that he would slip out of those clothes into his street wear and walk away from the scene undetected.

Watching the first time and Queenan’s death was brutally unexpected. What a great movie this is. An acting masterclass.

The elevator scene lives rent free in my head. I will forget that shock.

The cinematography shows you that Dignam knew Sullivan was the rat during the undercover buy at the warehouse.  As Dignam walks by Sullivan and asks "why the F did they turn their cell phones off?"   The camera precisely cuts multiple times showing Sullivan and Dignam in consecutive camera shots.   Perfectly done

I like to think Billy's letter was probably something like "Dignam is an asshole, but you can trust him"

I loved how Dignam knew Billy didn't kill captain Queenan. "That's a Fucking Lie!"

Madolyn probably gave Dingnam a key to Sullivan's apartment. No forced entry, no DNA, nobody ever found out Dingnam whacked Sullivan.

Dignam was the most intelligent character in the movie. Street smarts for days, smelled Sullivan was a rat early on, and I do believe he knew fully. And was able to breakdown and know who Costigan was before he had a chance to talk. Favorite character in the movie!

I always thought Madolyn's baby was actually Costigan's.

Can’t believe this film is already 20 years old!

Dignam more than likely suspected Sullivan due to his behavior throughout and the fact that he was the only survivor form the massacre in the warehouse while also the voice behind the radio when Queenan was murdered. Then he certainly got his hands on those tapes and files. In either case Dignam paying Sullivan a deadly visit wl always be satisfying. Sullivan dug his own grave and Dignam put him into it.

I think a more easier expression to digest about the final verdict at 5:40, rather than "This is who you are", is simply "Once a rat, always the rat": Sullivan will never escape being a snitch for the mob or being generally untrustworthy, even if Dignam didn't wind up killing him.

I always just assumed after Leo got killed and Damon's shady character walked away unscathed Dingham knew what was up. That guy was responsible for all of his friends deaths and he just didn't care to be lawful anymore.

It's almost like he had some sort of detective skills.

He didn't know until Sullivan said "Okay."  Hence the hesitation.

I thought it was pretty obvious from the film that Dignam suspected Sullivan. I don't think he needed instructions or an order on killing him. Also, it probably wasn't that difficult for him to find out where he lived.

The baby is Costigen’s. The last thing we hear her say was, “I thought I was the liar.” She lied that the baby was his. And she never got to tell Costigen because he stopped her from saying anything before he left.

Three people: Baldwin, Baldwin and Baldwin. He gave him two weeks suspension, with pay. Baldwin was his alibi. In the novelization, the narrator implies the two had an unorthodox relationship where they pretended to be warring factions against each other in the department, but that was their cover against potential internal corruption to work together to flush out any potential inner department cancers. Baldwin giving him the two weeks after just publicly brawling with the suspected mole and traitor within the department was an unspoken moment, eye exchange, of a contingency plan they had worked out prior amongst themselves should it ever come to this. The moment Baldwin sent Wahlberg home on suspended leave, that plan was already in motion.