I absolutely adored this episode. But somehow, I couldn't simply digest the weird ending. I really don't know why, probably the whole motive for the dad to kill the drug guy and Lassiter seemed too forced upon. It seemed something like, if the writers wrote material that concluded with something like Petrovich being the shooter, it would have been bland and cliched. At the same time, Salamatchia being the shooter provided the unseen and unexpected ending, however it was too forced upon and not too convincing as well. But that's the pitfall of Whodunnit shows like Psych and Mentalist.
Otherwise, this installment was sheer brilliance. This is easily the best mix of edge of seat tension and laugh out comedy. Now, I seriously wonder why this show is so underrated.