The Southland star made his debut as Boyd Fowler in last night's episode.
"I was dying to do it," he told TV Guide. "I enjoy doing all that [cop work], but to kind of stretch the muscles a little bit and step outside that world was exciting."
Hatosy also revealed that Boyd finds his job in the sanitation department "exciting", saying: "It's those kind of unusual things that the writers give you that you just kind of go with and accept. There's no reservation - you just kind of jump in. There's a youthful innocence to his joy in his work, and I think it's just fascinating."
Hatosy added that he was impressed that Boyd is such a well-rounded character.
"The writers on that show - they're so clever," he said. "They gave me a character that is one of the more complex characters that I've ever read, but human at the same time. The scripts are so thought-out. It raises the stakes... Inside the madness of the world they have created, there's something about it that rings true and honest. Even with the darkness, there's the underlying humour that comes out."
Dexter continues on Sundays at 9pm on Showtime.