Speaking to New York Magazine, the actress admitted that her feelings about the possible storyline change every day.
"There's a part of me that thinks Deb bleeds blue, and she's a cop through and through, and she would put him away," she said. "And then I realize that without Dexter she has no link to her childhood - there's no witness to recount stories and remind her of her origins. For that reason, I think that she might make a deal with him."
Carpenter also suggested that it is the right time for Deb to discover the truth about Dexter (Michael C Hall).
"I have a sense that the writers and producers have an idea of how that will unfold, and I'm ready to know," she said. "I feel like the audience has earned it as well. I feel like it's time for them to find out... I think it's kind of heading that way. I also feel like [Deb has] a lot of really integral puzzle pieces to the picture of Dexter - there's a lot of stuff that's difficult to ignore. I mean, I'm supposed to be able to know when people are lying, when they're hiding something, and I'm really good at my job. But I can't see the writing on the wall in front of me? Especially after I was dating a serial killer? I think it's time."
The fifth season finale of Dexter airs on Sunday at 9pm on Showtime.