Blue Bloods has Marisa Ramirez as a full-time cast member. This is a photo from Season 4.
Erin and Danny argue when she must release a suspect due to lack of evidence on the season premiere of Blue Bloods. "Unwritten Rules" is the first episode of the show's fourth season.

Blue Bloods Season 4 Episode 1 Quotes

We decline to charge suspects every day. Many of them are guilty but you still need evidence.


Jamie: I thought I was just another cop.
Frank: You are. You're also a lawyer and you'll understand the why of this more than most.