'Blue Bloods': Reagan Family Member Makes Life-Altering Decision in Season 12 Finale

The Blue Bloods Season 12 finale packed in two major character developments before closing the curtain on another year. A.D.A. Erin Reagan (Bridget Moynahan) finally committed to making that big move she has been debating about all season, while Det. Maria Baez (Marisa Ramirez) added one to her family. Before those developments though, "Silver Linings" delivered plenty of drama.

The major story involving Commissioner Frank Reagan (Tom Selleck) and D.A. Kimberly Crawford (Rosyln Ruff) began with Frank calling out her office for downgrading felonies to misdemeanors and releasing criminals hours after their arrest. Frank said Crawford's office was "failing" the city and drafting charging guidelines that are in violation of her office. Frank's biggest disagreement with Crawford was over their different definitions of "non-violent crimes." He even wanted Crawford's A.D.A.s to ignore her guidelines and should speak out. Erin watched the conference in her office and was not happy.

Throughout "Silver Linings," it became clear that Frank and Crawford could not easily see eye-to-eye. Erin also did not enjoy watching her father call out her boss on television. When Erin and Frank argued in his office, he admitted to believing Erin would make a good D.A. Then again, he told Erin he didn't want her to make a decision based on what he thought. Frank said he thought she was afraid of running, not because she was afraid of losing, but because she was afraid of winning and the responsibilities that come with it.

There was a very poignant scene partway through the episode between Erin and Anthony Abetemarco (Steven Schirripa), who was growing tired of Erin complaining about Frank caring so much about her career. He reminded her that she's lucky to have such an attentive father and that the Reagans gather for Sunday dinner every week. He was raised by a single mom and barely knew his father. This conversation inspired Erin to finally invite Anthony to the family dinner later in the episode.

The differences between the D.A.'s office and Frank were never really ironed out. Crawford and Frank kept telling Erin that nothing between them was personal, but Crawford did finally admit that she's never been happy that a Reagan is in her office. Erin might have never brought up that in her cases, but Crawford reminded her that it doesn't matter. The fact that Erin admitted she agrees with Frank that some of Crawford's mandates will make the city more dangerous just made Crawford's case.

Later, Erin reminded Frank that she doesn't publicly complain about the police out of respect for her dad, which is why it hurt to see him do just that about her office. He also made it impossible for her to talk about the issue with Crawford without Crawford seeing her as "the commissioner's daughter." Erin also said the real reason she wasn't running for D.A. was her fear of losing. "It's your fault... for raising me with three brothers," Erin said.

However, between that scene and the Sunday dinner, something changed for Erin. She happily announced to the family, Anthony, and Joe Hill (Will Hochman) that she will be running for D.A. That will set up the main story for Season 13, which is definitely coming after CBS renewed the series. "I may be afraid of losing, but I think if I have your love and support, I'll be unbeatable," Erin told everyone. "Spoken like a true Reagan," Danny (Donnie Wahlberg) said.

Elsewhere in the episode, Baez and Danny investigated the murder of a woman in witness protection. Their cases converged with Joe and Jamie's (Will Estes) investigation into the disappearance of a trafficked teenage girl. The victim was pregnant, and her baby was saved. Baez adopted the baby, and Danny said he would always be there to help.

Blue Bloods will be back for Season 13 in the fall. Past episodes are available to stream on Paramount+.