NEW YORK -- Joel Kinnaman had his "aha" moment on "The Killing" while shooting an episode of the AMC crime drama early last season.
The scene called for Stephen Holder, the Seattle Police detective Kinnaman portrays, to chat up two high school girls. Holder was investigating the grisly murder of local teen Rosie Larsen and he thought these girls knew something.
"The Killing"Season finale airs at 8 p.m. Sunday, June 15, on AMC
So he offered them the joint he was smoking.
"I'm off the clock," he grinned, glassy-eyed. "It's not like I'm gonna ARREST you."
"That's some crazy sick weed," declared one of the girls after letting out a lung-full. "I'm SO stoned right now!"
"So are we gonna party?" Holder slyly suggested.
A moment later, they had spilled the information he was looking for, whereupon he dashed off, leaving them bewildered -- and not really stoned (it wasn't really marijuana).
The girls had bought his ruse. So had the audience. Scruffy, gangly and shrewd, Holder fools everyone.
"It was such a great way to present that character, and I was so inspired by that scene," says Kinnaman. "You ask: Who is this guy? Do I like him? Do I not? Those are questions I really want asked about the characters I play. It's so much more interesting to be in a moral gray zone."
Teamed with prickly, pushy Detective Sarah Linden (series star Mireille Enos), Holder has kept viewers guessing for two seasons (or, in narrative terms, 25 successive days) as the grim investigation ensnares much of the Seattle community, including the mayoral race of Councilman Darren Richmond (Billy Campbell), whose campaign team may be tied up in the crime.
On the season finale, which airs at 8 p.m. Sunday, Holder and Linden will finally crack the case. That's not a moment too soon for restless viewers, some of whom thought they were promised the Big Reveal a year ago but got a cliffhanger instead.
"It was a little bit of mismanaged expectations, marketing-wise," says Kinnaman, "so some people felt tricked."
Even so, the time has come on this heavy-hearted whodunit to find out Who Killed Rosie Larsen.
But whoever the culprit turns out to be, one thing has been clear since the series premiered: Holder -- an ex-narc and recovering addict -- is an endearing eccentric infused by Kinnaman with grit, nuance and the lone measure of comic relief in a series that otherwise is shrouded in gloom.
Giraffing over his pint-size partner, Holder is a blend of hip-hop-spiked Úlan and fidgety insolence -- "'Sup, Linden? Oh, snap! You know you're my BFF," he carries on with her between cigarette puffs.
Another thing is sure (this hardly rises to the level of a spoiler): Holder isn't the killer.
Kinnaman scrunches his face dismissively at such a notion: "That would just be stupid," he says. "And it's not a stupid show."
What did he think when he learned who did the deed?
"I was surprised," he allows. "Yeah, it was cool. It was very satisfying."
Kinnaman is chatting with a reporter in his Manhattan hotel suite. In person, he strikes a marked contrast to Holder, a skulking presence forever hunched in his hoodie. Kinnaman is rangy and strapping in a T-shirt, slacks and running shoes, and notably spared Holder's ghostly pallor.
"When I'm playing Holder, I feel like it affects my skin," Kinnaman confides. "Even when I was rested and got exercise."
Kinnaman's co-star, Enos, summed up his presto-chango act this way in a phone call from Los Angeles: "Off-camera, he's movie-star handsome," she said, "and then he shows up for a scene so willing to make himself vulnerable and awkward and scrappy."
Kinnaman was born 32 years ago in Stockholm, the son of an American father and a Swedish mother.
His older half-sister Melinda has been an actress from childhood (she made her debut as the tomboy Saga in the 1985 classic "My Life as a Dog," directed by Lasse Hallstrom), and when Kinnaman was 10, he spent a year in the cast of a Swedish TV series, "Storstad."
"It was a soap, and horrendously bad," says Kinnaman. "But it was watched by 30 percent of the population. It was a cool experience."
At 12 he retired ("by then, I was into being a tough guy, and acting wasn't part of being a tough guy"), but by his early 20s he was back in the game.
He attended the prestigious Swedish Academic School of Drama, and won roles in a string of projects including "Snabba Cash" two years ago, which became Sweden's highest-grossing film.
Set to be released in the U.S. this summer retitled "Easy Money," this pressure-cooker thriller finds Kinnaman as a business student seduced by the fast life of organized crime and its drug trade.
Also this summer, he appears in the romantic comedy "Lola Versus" as the longtime boyfriend of a young New York woman (played by Greta Gerwig) whom he dumps three weeks before their wedding.
"It was fun and smart, and I loved the theme of the movie: freedom through solitude," says Kinnaman, who in his late teens roamed the world by himself for two years as his own exploration of solitude.
This fall he heads to Toronto to star in the much-anticipated remake of "RoboCop," directed by Jose Padilha, with Samuel L. Jackson and Gary Oldman also in the cast.
"I was chasing a big movie," says Kinnaman, hoping with it to gain the sort of box-office clout that expands his acting choices, "and I feel so lucky it's this one. I don't feel like I'm about to do a big action movie. This feels like a drama about what it is to be human. That's the core of this movie, even though it comes equipped with fireworks and cool gadgets and CGI."
Kinnaman's career has moved at warp speed since he arrived in Los Angeles three years ago. But he left his homeland with admitted trepidation.
"I was afraid of coming from the European art scene to Hollywood, where I expected to find more vanity and ego, the two poisons to creativity," he says.
But when he won his first American job, "The Killing," he found quite the opposite from Mireille Enos: "She leads with generosity, and her vanity is nonexistent. She brought out the best in me."
"We have a similar perspective on storytelling," Enos said by phone. "We both believe that weird, awkward humanity is more interesting than things in nice packages."
As TV's most awkward but delicious odd couple, their matchup was casting kismet: Before each was signed, they had never even read together.
"We met each other on the plane up to Vancouver to film the pilot," Enos said, "and by the end of that flight, we were pals."
But as the season finale of "The Killing" nears, with its resolution of a mystery stretching back to its premiere, the future of the series remains a mystery. AMC has not yet said if the show will be renewed.
When asked about that, Kinnaman looks unperturbed.
"I'm planning on doing the third season of 'The Killing,'" he declares with a determined smile. "I'll go up there and shoot it myself."