‘Boston Blue’ Episode 19 Recap – This Time It’s Personal

By Jonathon Wilson - May 16, 2026
Mika Amonsen, Donnie Wahlberg and Sonequa Martin-Green in Boston Blue
Mika Amonsen, Donnie Wahlberg and Sonequa Martin-Green in Boston Blue | Image via CBS

WARNING: THIS ARTICLE CONTAINS MAJOR SPOILERS

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Summary

Boston Blue gets personal in “Chasing Monsters” with a cop-killer A-plot and some much-needed revelations in Lena’s search for her birth father.

You’d think that criminals would have learned by now that shooting cops is probably a bad idea. In a show like Boston Blue, which is redolent with affection for the badge, it’s an even dumber idea than usual. Despite this, though, Episode 19 uses its cop-killer case of the week to delve into the character implications in a pretty engaging way, while also continuing the subplot about Lena and her birth father, which reached a turning point in the previous outing. I thought it was pretty good, continuing a run of late-season form for the CBS procedural.

Danny, Lena, Sean, Jonah, and even Sarah are all pretty intimately involved in the A-plot, which leaves less room for pointless shenanigans elsewhere (Mae trying to keep a hold of her job notwithstanding). I’ve said it before, but this show really benefits from a tighter focus instead of spreading its drama really thin, and these kinds of cases help to bring everyone together in a way that feels logical but doesn’t neglect the individual perspectives and character arcs.

It’s Sean and Jonah who are on the scene to begin with. The shooter targets another pair of uniformed officers on their patrol shift while they’re off getting cannoli, so it could just as easily have been them. That knowledge, as well as the reality that one of their own has been targeted, shapes their perspective on the upcoming manhunt. When it’s discovered that the killer left behind a manifesto insisting the police were corrupt and repeatedly citing “2172”, which is the number of active police in the department, it becomes obvious that the killer is hunting cops as part of a wider campaign. Stakes raised.

The victim dies, but his partner, Rachel, is left to pick up the pieces. Interestingly, bodycam footage reveals that rather than shooting back at the suspect, she prioritised saving her partner, which internally raises some questions about her suitability for policework. Did she abandon her training out of cowardice? Or did she consider saving the life of her colleague more important than taking the life of his killer? This is primarily how Sarah gets involved, as she – rightly, in my view – advocates for Rachel against the more old-school, vengeful sentiment that is common among the higher-ups.

Naturally, Sean and Jonah have to deal with the guilt of Steve having been shot while covering their zone for frivolous reasons. Sean tried his best to save Steve, who later died in the hospital, so he takes the death especially hard, and it makes him reckless. This prompts Sean to step in a few times and give him some fatherly advice about controlling his emotions, which we know is a subject he’s pretty well-versed in, given his own career. Again, this is a smart application of the character dynamics. It plays on Blue Bloods in a way that doesn’t feel forced or exclusionary for people who didn’t watch it.

The killer’s motive in Boston Blue Episode 19 also feels pretty on brand. The culprit is a guy from a cop family who was bounced out of the academy for being unstable, but didn’t feel as if he was able to cope with that rejection, given how integral the police were to his bloodline. That’s something that both Danny and Lena can relate to, given their own family circumstances. It’s a nice reminder that law enforcement isn’t all sunshine and rainbows, and that the job isn’t for everyone.

Speaking of family circumstances, we might as well briefly talk about Lena. This is another of those classic procedural A-plots that help a lead character to deal with some ongoing predicament, and so it is with Steve’s funeral, helping Lena to decide that she doesn’t want to spend her life not knowing where she came from after all. This is helped along by Mae finally confessing the truth of the situation. Her birth father did know about her, and more to the point, he wanted to be involved in her life. Mae didn’t let him. She thought it would have destroyed everything she had been able to build. Now that’s out in the open, she and Lena can probably build some bridges, but it’s likely to take a while yet. Either way, though, “Chasing Monsters” ends with Lena calling her dad to speak to him for the very first time. We’ll see how she gets on with that next week.

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