Agreed, a very strong episode from the pen of Moira Kirland. As a rule, I'm not fond of the cliche of the cop getting involved in a personal case and letting his emotions drive him forward against all good judgment, advice, and procedure. But it was ameliorated here because Ryan didn't go in guns blazing and wanting to kill someone, but remained focused throughout on seeing justice done, on putting the bad guys in custody rather than in the ground, and his big act of "going rogue" was going to the younger brother and appealing to him on a compassionate level to do the right thing. What drove him wasn't vengeance but an overpowering sense of responsibility.
Anyway, the promo for this one last week was really misleading. It made it look as though Ryan was the suspect in the murder. But that wasn't the direction it went at all. Still, I guess a misleading promo is better than one that gives away most of the actual plot.