Dexter.

We know that Dexter was born in blood — but what about that army green shirt he’s been wearing since the pilot? What’s the shirt’s origin story? With Dexter beginning its eighth and final season on Sunday, we rang up the show’s costume designer, Kathleen Felix-Hager, to find out. “The thought behind it was that he has his sort of everyday, lab-geek persona at work,” she says. “He wears bright colors and these poppy ice-cream linen shirts and khaki pants. But then when he’s the serial killer, when he puts on the stalking shirt and the cargos, it’s sort of a darker Dexter.” A darker, sexier Dexter. Here’s what else we learned about his kill clothes. (Plus: Michael C. Hall gets sentimental over footwear.)

1. The army green shirt, commonly referred to as Dexter’s kill shirt, is actually called his stalking outfit, according to the scripts.
“There are two separate things that we refer to when we break down the script: the kill outfit and the stalking outfit. The stalking outfit is the Henley shirt and the cargo pants and his leather boots and leather gloves. It’s sort of like Dexter’s superhero costume. And then when he does his actual kill, there’s what we refer to as the kill suit; it’s a custom-made jumpsuit that’s sort of like a flight suit that zips up the front. We made eight of them.”

2. The stalking shirt is indeed meant to show off Michael C. Hall’s hot body. 
“Michael has a fantastic body … it really shows off his shoulders and muscular arms and small waist. When we see him in the lab or at a crime scene, you don’t see his shape. When you see him put on this superhero costume, you see how powerful and strong and quick and agile he is.”

3. Michael C. Hall has worn the same leather stalking boots since the pilot, and he plans to keep them when the show wraps.
“We have multiples of them — we have extra pairs for stunts and for doubles and things like that. But Michael C. Hall himself wears this one particular No. 1 pair of boots. I think that’s one of the things he wants [to keep], funny enough.”

4. The other thing he’ll probably keep is Dexter’s I.D. badge.
“Otherwise, I think he’s ready to leave most of Dexter behind!”

5. The stalking shirt is by American Apparel.
“It’s the Baby Thermal Henley in army green. I assume they know it’s their shirt. They’ve never complained about it. But they’ve never said, ‘Here, we’d love to give you five dozen free shirts,’ either. So I think they’ve just sort of distanced themselves from it, neither good nor bad.”

6. There are two dozen shirts on hand at any given time, so if American Apparel ever discontinued them, the show would have been okay. “Same with the cargo pants. They are Paperback Cargo. And we have them in various sizes so we can accommodate stuntmen or if anyone needs to wear pads.”

7. The costume department can’t give away old shirts because overzealous fans might find out and go nuts.
“We toss them. People are obsessed with them, so we don’t really give them away. I think when everything wraps up, Showtime is going to auction off a lot of the costumes.”

8. That auction could also include Batista’s hats or Deb’s aviator sunglasses.“She’s worn those all eight seasons also. They’ve never broken or gotten lost. We can see her eyes through them — which, when you see her outside, she’s got these gorgeous eyes and so much of her acting is done through them.”

Dexter’s Kill Clothes Are Sexy for a Reason