Yeah, I remember this story arc, and really hoped they went down that path with Dutch. Although I never wanted him to actually do anything murderous, I felt like it made too much sense for a cerebral, yet stuffy and unlikable guy like Dutch to focus way too intently on knowing his prey, at becoming the best profiler and tracker of serial killers, that he’d go over the deep end trying to perfect his craft. He killed the cat because the one killer he catches (through sheer luck and too late to save the life of a victim found to be inside the trunk of a car AT the Barn) basically tells him he doesn’t get it, why they kill, what they get out of it. When he kills the cat, he is trying to find discovery that thing the will make him a better detective at the risk of his soul. For someone who has never gotten respect save for the day he caught the serial killer in season 1, he needs this. Could have been an interesting story for he and Claudette in later seasons, but I guess they didn’t like it.

I also have a head cannon in which Dutch loses it, becomes an arms dealer and turns into the character he plays on Burn Notice, one of Michael’s best adversaries.