MICHAEL C HALL: 'I don't aspire to write the show, but I feel that I am the guardian of my sense of Dexter's truth as much as it exists.'

Television's favourite serial killer came close to having a different face.

Having just finished five seasons on Six Feet Under, the last thing Michael C Hall wanted to do was to jump into another open-ended commitment.

But the more he read the script and Jeff Lindsay's novel, Darkly Dreaming Dexter, the more he thought about the possibilities for the character – a Miami police department blood-spatter analyst who has a compulsion to kill.

LAWRENCE SMITH/Sunday News MICHAEL C HALL: The actor believes Dexter's affection for Harrison actually makes the show more disturbing.

"I took a couple of weeks to make a decision, but I couldn't pass up the opportunity to try to pull off what the show aspired to do, which was somewhat subversive, inspiring an audience to identify with and even root for a serial killer," Hall says while visiting Auckland to promote the show and "have a holiday" this month.

Born in North Carolina, Hall says his first acting experience was a church production at the age of six. "I remember the sense of invigoration I had just walking around my house learning my lines, highlighting my lines, and the feeling of exhilaration when I finished the show.

"Looking back, perhaps the die was cast (that I would be an actor) right there, but I didn't admit that was what I dreamed of until I was in college and had exhausted other liberal arts education possibilities and took an acting class. It was then that it became undeniable to me that this was the thing I had the most enthusiasm and aptitude for."

To prepare for the Dexter role, Hall sat down with Miami-Dade Police Department's blood-spatter analyst expert to get a sense of what his job was and watched a documentary about the lead analyst in the OJ Simpson trial.

"It gave me a sense of the nuts and bolts of what the job entailed, as well as a sense of the politics within a police department."

One of the unique aspects of the show Hall had to get used to was the extensive use of voice-over.

"It's a big part of the performance. Without it, I don't think audiences would have the same relationship with the character because you're hearing secrets that no-one else in his world is privy to and you're almost his silent accomplice.

"I initially attempted to record it while shooting, but found I wasn't comfortable recording it blind – there's so much nuance that you can find if you record it to picture. So now I have a recording device in my trailer and, while shooting an episode, I'll lay down a scratch track that we re-record when we do the final sound mix. It really brings it to life and makes it feel organic, integrated and fundamental."

An executive producer on the show, Hall sees that role as more than just a vanity credit because of the subjective nature of the series. "Dexter isn't privy to everything on the show, but we do hear his thoughts and see and consider what happens at least to an extent through the prism of his subjective experience.

"I don't aspire to write the show, but I do feel that I am the guardian of my sense of Dexter's truth as much as it exists."

He says his contribution varies from season to season and episode to episode. "I think my contribution is not about what happens, but how it happens."

Hall's professionalism and commitment to the role are best illustrated by what happened towards the end of filming for season four, when he discovered that he had Hodgkins' lymphoma.

Carrying out the initial staging tests while completing production, he started treatment the day after they wrapped and completed it in time for season five. Unaware of his health problems, his fellow actors were shocked to discover what he had been battling.

"I simply had a wig made for the fifth season and didn't miss a beat production-wise. I was very lucky."

Since then he has been more than happy to lend his time or face to the Lymphoma Society's cause. "If that helps them generate money for research, then I'm all for it."

Hall says a typical shoot involves 12 to 16 hours a day, five days a week for 4 1/2 months.

"When you're in the midst of the season, it's hard to decompress, even if you get a weekend or an evening off. And it is the same to an extent with the hiatuses between seasons. It is still looming, still there waiting."

That means it is nice to do something else during that downtime, he says.

"Even if it's an inconsequential film that no-one might see, such as 2009's much-derided Gamer, sinking my teeth into something different goes a long way to recharging my batteries. But I probably won't be able to appreciate the decompression or how much character stayed with me until all is said and done and it's over."

Dexter: Tuesdays, 8.30pm, SoHo.