The episode story is nothing special here. Typical police procedural, feels like CSI: Hawaii. And the more they use Masi Oka, the more diluted his character becomes: less autistic, and with a new talent and interest every week which just happens to tie into the current case. He's becoming boring.
The season story arc involving Shelbourne continued to move at its glacial pace, with no new revelations. Go ahead, writers, keep stringing it along.
Worst to me in this episode is the use of Tom Sizemore. Did someone on the exec team owe this actor a favor? He's straight out of an Italian gangster movie, and in this episode, plays up the role, while the others watch his over-the-top interrogation tactics and don't even blink. Scott Caan as one New Jersey import is believable, but a second mafia policeman is just ridiculous.
I loved the idea of this show, and the focus was much better when it stayed with the central team. Keep the show about Steve, Danno, Chin, and Kono (and Wo Fat), and this show will rebound. Make it about the fringe actors, and it's doomed.