Detective Stella Bonasera: What would a woman be doing in the men's bathroom?
Detective Don Flack: I can think of several reasons. All with happier endings.

Detective Stella Bonasera: Witnesses? Sober ones anyway?
Det. Don Flack: Nah. I waited for you to get here before I started my interviews, looking forward to that by the way. I swear to you, if one of them calls me "bro"...
[Don is questioning a fraternity member with alcohol bottles taped to his hands]

Detective Stella Bonasera: You let a lady walk home drunk? What a gentleman you are.

Detective Stella Bonasera: You remember yesterday when you asked me if I wanted to break some rules? I do now.
Detective Danny Messer: You want to break some rules?

Detective Stella Bonasera: Your divorce was finalized a week ago. The judge who presided over it was just found dead. What would you call that?
Larry Rose: A happy coincidence.
Angell: Is that supposed to be funny?
Larry Rose: Depends. You have a sense of humor?
Angell: Depends. You're funny?

Detective Stella Bonasera: [about the weirdness of the crime] Is it me or is there something really strange about this crime scene?

Detective Stella Bonasera: [at the same time as Mac] Who discovered the body?
Detective Mac Taylor: [at the same time as Stella] Who discovered the body?
Detective Don Flack: You two've been working together way too long. A student came in looking for her keys and "boom".
Detective Mac Taylor: Boom? You and Danny have been working together way too long.

Detective Stella Bonasera: [Reading from a piece of paper the victim had in his sock] "In my darkest moment, when all seems lost, you are at my side."
Detective Mac Taylor: [Coming up from behind] I appreciate you too, Stella.

Detective Stella Bonasera: [walking into his office] Mac, where the hell did you go last night? I called you repeatedly, looked all over the street. You just vanished.
Detective Mac Taylor: I was with the FBI... They picked me up in a car and questioned me for over an hour about the Ann Steele case.
Detective Stella Bonasera: The fixer with the flash drive.
Detective Mac Taylor: I was the last one who handled it. They accused me of stealing it.
Detective Stella Bonasera: What?

Diane the lawyer: My client has nothing to say.
Stella: That's okay. I'm in a chatty mood. [Behind her, Flack smirks]

Don Flack: I'm facts, he's science.

Don Flack [about Michael]: Maybe he decided to do us all a favour and took himself out.
Danny Messer: It's hard to tell in this place but I am seeing indications of a struggle. And if he took himself out, where's the gun?
Don Flack: Could be under his body.
Danny Messer: (checks) No. No gun here.
Don Flack: Well, I'm no expert but I've seen enough guns in my time to know that they don't just grow legs and walk away.
Danny Messer: No, he didn't commit suicide. Michael Reynolds was murdered. What a life. He gets kidnapped, kept for three years, escapes... only to be murdered 12 years later.

Don Flack :[about Paul Benson] I don't get it. This guy was the senior class president, captain of the soccer team, Dean's list. This kid had everything going for him back in 2002. He was the guy you love to hate in every John Hughes film.
Danny Messer: He was even dating the prom queen, Sarah Dufresne.
Don Flack: Apparently dating her wasn't enough (reads from Benson's file) "I told him I wanted to wait, that if he loved me, he would respect that I wanted to wait. He grabbed my arms and pinned me down." One minute he's Harvard bound, next he's Rikers bound.

Don Flack: ( Sees half naked woman in the body painting studio.)Are you free for something tonight?
Jo Danville:( Pulls Flack out from the room.) Flack, go!

Don Flack: (About Mike Black) He's either an amazing liar... or I'm not as good at this as I think I am.