When American actor Walton Goggins signed on to play Bible-bashing outlaw Boyd Crowder in the debut season of Justified; it was supposed to be a one-off appearance, a brief sparring with his old mate, Timothy Olyphant.

Olyphant, who plays sharpshooter Marshal Raylan Givens, was nominally the star of Justified, which is based around the short story Fire in the Hole by American crime-writing master - and dark humorist - Elmore Leonard.

But as the show, set in the city of Lexington and rural Harlan County, Kentucky, took off to great acclaim in the United States and Britain, and the series kept being extended, Justified briskly evolved into what one critic has described as the "Raylan and Boyd show", a nuanced pairing where enmities have shifted and Boyd, originally defined as one of the "bad guys", has morphed into a more complex, interesting character.

"Boyd was only supposed to be in the series for a short while," says Goggins. "But one of the greatest things about a character like Boyd - and this doesn't happen very often in television - is that you have a character who was supposed to die and there's a series of events where he ends up living.

For me, we could go anywhere with Boyd. Me and Graham [Yost, the screenwriter] really got to talk about Boyd and how he could participate in the show and bring something to it that would have been missing otherwise. And that is just exciting," he hoots. "I'd invite Boyd to my party! I'd have a cold beer with him!"

Although series one and two of Justified - which feature, among other things, an unholy alliance of meth, moonshine and a murderous matriarch - screened here a couple of years ago, you may have missed it as TV One wasted it in a late-night slot. But now SoHo takes up the slack from next Tuesday, running the first two series before launching into the third round. Series four started screening in the US at the beginning of this year, with the fifth given the green light for 2014. And so the "Raylan and Boyd show" rolls on, a billing that Goggins politely takes issue with.

"Boyd is there as a service to Raylan Givens and that story, and I have no problem being number two to the likes of Timothy Olyphant. He is an extraordinary actor but I think our strength lies in exploring both sides of the coin. In some ways, Raylan needs Boyd, he needs that history and that connection with a person who is as smart as him."

The "history" is that both men come from similar backgrounds, with harsh relationships with their fathers that continue to wreak havoc in their adult lives. Boyd and Raylan recognise - and grow to respect - each other's strengths and neuroses.

"What is so interesting about the potential in that structure, that dysfunctional friendship, is that, weirdly enough, they are kind of mirroring each other," says Goggins. "At some point these histories and the mirroring of these relationships they've been having independently with people are going to come together in a way that will be very surprising."

Goggins, 43, who grew up in Alabama and Georgia (hence his soft, drawling accent) says that though Justified is not shot on location in Kentucky, it is filmed in "rural communities" in California and "we are as authentic as we can be, given the budget".

"We get a lot of reaction from the people of Harlan County and that's the most important voice out there. They like what we do. I am from Georgia and there is no way I would be part of a piece of fiction that talks down to or makes fun of my culture and the people of Harlan County see that. We represent the people who are really smart and the people who are dumb-asses."

One of the most dumb-ass families in the show is the yokel Bennett clan, led by scary mama Mags, who is smart but has three incredibly dimwitted sons. Margo Martindale, who plays Mags, won an Emmy for her work in Justified's second season, with Olyphant and Goggins also nominated the same year.

The Mags-Boyd-Raylan triangle is all about the struggle for control of Harlan County, says Goggins, who hints that in series three, the mix will be further scrambled by the arrival of what he calls "an urban element ... anyone looking to make a quick buck, taking advantage of an economy in a shambles".

Goggins has interests beyond acting, running a production company called Ginny Mule Pictures with his business partner Ray McKinnon. Their short film, The Accountant, won the 2001 Academy Award for Best Live Action Short Film, while That Evening Sun won a South By Southwest Special Jury Prize in 2009.

But it is, until now, his six years of playing anguished cop Shane Vendrell in The Shield which has won him the most attention. Shane, who murdered a colleague to protect his Strike Team boss, Vic Mackey (Michael Chiklis), spent most of the last season in a state of extreme paranoia, on the run from the relentless, brutal Vic.

"It was emotionally exhausting," he recalls. "It was as if Shane was always the last guy walking into the room, he always had the information 30 seconds too late. It was so painful to love a character so much whose fate had already been written before he came into this situation.

"It broke my heart. I still have his jacket and badge ... but in some ways I am really happy that he died. Now I don't have to think about what Shane's doin'."

What: Justified, Kentucky-based crime drama rescreening seasons one and two before launching into the third (not yet seen in NZ) series
Who: Walton Goggins as Boyd Crowder, evangelising "villain" and anti-drugs crusader contesting turf with Timothy Olyphant's Marshal Raylan Givens
Where and when: SoHo, Tuesdays, 9.30pm

- TimeOut