I think after they introduced the Trinity Killer the series struggled, especially with Rita dead and Dexter more or less kind of in arrested development.
The last season was absolute garbage that chose tawdry symbolism over coherence and substance.
I agree, it was a pitiful end to what was a great show.
Yes, the Trinity Killer was the highlight season of the series. They filmed nearly the entire show in my small neighborhood at the time. We were taking a walk one evening and onehouse was taken over by filming. As we walked by, we asked what they were filming, and they said Dexter. I said, “Oh, a kids’ show.” And they stared at me, shook their heads, and said, “ NOT. NOT a kids’ show.”
So I started watching. Almost all the characters lived within 3 blocks of each other. They filmed there for years; it was fun to watch. Trinity, his first wife, LaGuerta, Jimmy Smits, etc. They blew up (in miniature) a landmark house two houses from ours.
Yeah, the last season really sucked.