Dexter's John Lithgow Talks About the Shocking Finale

[SPOILER ALERT: This article contains key plot details from Sunday's Season 4 finale.]
Dexter may have killed Arthur Mitchell, aka the Trinity Killer (John Lithgow), in the Season 4 finale of Dexter, but not before Trinity murdered Dexter's wife Rita (Julie Benz). TVGuide.com sat down with Lithgow at the Dexter finale party Sunday to hear his thoughts on the game-changing developments. Lithgow also discussed how the serial killer was almost spared from Dex's table and if he'll be returning to the show post-mortem.
TVGuide.com: First off, the season finale of Dexter was just heartbreaking.
John Lithgow: Isn't that something? "Wow" is the word.

Check out the full finale recap of Dexter

TVGuide.com: Trinity is so far from what we've ever seen you play.
Lithgow: Well, that was exactly what I loved about it. I knew I really had it in my power to shock people, not just because it was a great role and brilliantly written, but because of everything that I've been doing for the last 10 years. I'm most familiar to people as the very amiable, ridiculous character Dick Solomon [from TV's 3rd Rock From the Sun]. The Trinity Killer's first victim was High Commander Dick Solomon. I just shocked the daylights out of people, including my wife. At the end of every episode, she'd look at me as if to say, "Who are you?!"TVGuide.com: Did you know from the beginning that Arthur was going to die at the end of the season?
Lithgow: Yes, I did. On the other hand, they kept calling audibles. They changed things based on how the first several episodes went. I know they had long discussions: "Should we let Arthur get away, disappear for a season and then come back again?" That's what they did with Keith Carradine and it was incredibly effective. I think Arthur was so bad that they knew blood had to be spilled, especially when they came up with the final image of the episode. What an appalling, unforgivable thing to do. There had to be retribution.TVGuide.com: His legacy lives on with that scene.
Lithgow: Yeah, that was his calling card.TVGuide.com: Have they talked to you at all about coming back next season since Dexter does see ghosts?
Lithgow: Nobody has said anything. I think it's best because you couldn't possibly top this season and this character.

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TVGuide.com: What was the best part about working on the show this season?
Lithgow: There were certain scenes that were so extraordinarily well structured and so much fun to act. They all involve Michael C. Hall. Michael is a marvelous acting partner. The scene that begins the final episode, where I speak to him in that huge crowd and I know I have him exactly where I want him. I loved that scene. He was so great at working out the rhythms and finding the real meaning when the scene shifted. I loved my death scene with him and that appalling moment where I learn my own daughter committed suicide. It's very unusual for a character that despicable to have a moment like that, a moment of such pain.
TVGuide.com: Did you like that we saw those brief moments of anguish in Arthur?
Lithgow: Yeah, what I found most fascinating about the character is that he does appalling things and he hates himself for doing them, but he's got a compulsion. I just thought that was a very interesting inner conflict. Even when he's beating a man to death with a hammer, you see this terrible, terrible grief in his face. I thought that was a terrific conflict.
TVGuide.com: Was it hard to become such a despicable character who actually murders people?
Lithgow: No, that's what I do. [Laughs] You're always elated when a scene goes that well.
TVGuide.com: Any wish that you could've turned that tables and killed Dexter?
Lithgow: It wouldn't have been right. I needed to go. The character himself knew he needed to go. He was almost begging Dexter to do it. Look, he tried to commit suicide three episodes before. He knew this had to stop. If nobody else is going to stop me, I have to stop it myself. It's fascinating.

TVGuide.com: How do you feel coming into awards season having played a character with such depth?
Lithgow: I can honestly say I do not think about it. I felt like the whole Dexter experience ends tonight. It really ended on Oct. 13 when I finished shooting. Tonight, the great experience of unveiling it to the public is all over, so I feel very melancholy about tomorrow. As far as awards, I love getting awards. It's all very exciting. I suppose I would be disappointed if I didn't get nominated, but I try not to think about it because I think it's very corrupting. I don't want anything to take away the No. 1 priority, which is how great the experience was.
Were you sad Arthur killed Rita in the season finale?