Oscar-winner Colin Firth reveals he wasn’t a true crime fan until The Staircase changed his mind

Oscar-winner Colin Firth is best known for his nice-guy roles, but he reveals how the quality of true crime saga The Staircase convinced him to play a convicted killer.

Tragic accident or gruesome murder? Who – or what – killed Kathleen Peterson has been a topic of heated debate ever since her husband, Michael, called 911 claiming he’d found his wife lying at the bottom of the stairs of their palatial North Carolina home.

Since that fateful night in 2001, all sorts of theories have emerged about Kathleen’s death. Did she simply slip down the stairs after enjoying a few wines after dinner, as Michael insisted? Or did the crime writer bludgeon his wife with a fire-poker after she discovered he’d been having affairs with multiple men? Or – perhaps strangest of all – was Kathleen the victim of a vicious wild owl attack?

While these mysteries were examined in forensic detail in the 2004 documentary The Staircase, one of the most important questions has remained unaddressed and unanswered, until now.

Who was Kathleen Peterson? Sadly, the woman at the centre of this true crime has remained a bit player in her own murder story, relegated simply to being the body at the bottom of the staircase rather than a fully fleshed human being. Until now.

A new drama series (also called The Staircase) starring Toni Collette as Kathleen and Colin Firth as her accused killer, aims to right this wrong and will, for the first time, seek to present audiences with a clearer picture of Kathleen’s life.

Colin Firth and Toni Collette in a Scene from the Binge crime drama The Staircase.

Writer and producer Antonio Campos says they had approached six-episode series as a “family drama more than a crime show”.

“Exploring the events leading up to that night and after that night, in some way, felt like we were getting closer to something like the truth than sort of staring at a bunch of evidence and going over a lot of the things that people get obsessed about with this case, whether it be the bloodstain pattern or the shape of the lacerations and things like that,” he explained.

This approach is what appealed to Firth, who admits he has never been a true crime buff. Best known for his loveable but straitlaced roles in Pride and Prejudice, Bridget Jones’ Diaries and Love Actually, Firth says he hadn’t actively sought to shatter his nice guy image by playing a convicted killer.

“It was a very simple case of thinking this was a good script,” Firth explains.

“It wasn’t really initially what I thought I was looking for. True-crime genre isn’t where I go for my entertainment particularly. I just was struck by the quality of the writing, and I found the whole thing very intriguing.”

Of course, because of the intense interest in the case – the Oscar-winner was spoiled for choice when it came to researching his character. While he watched the documentary as well as other interviews and outtakes with Michael to get a better sense of his mannerisms and speech patterns, Firth ultimately decided not to meet the man himself for fear it could influence his performance.

“We all know that these characters have names of living people, but it’s very carefully calibrated to tell the story in a certain way, and I felt that I wanted to keep my inspiration, my motivation, and the sense of the source material as much as possible contained within the script and the way it was written,” he explains.

Colin Firth says he wasn’t a true crime fan but the script for The Staircase turned him around.

“And I felt that that could have been skewed in some way if I had personal connections during the shooting of this with Michael Peterson or the people concerned.”

Firth emphasises that this drama series does not set out to answer definitively whodunit but rather to explore the different possibilities and give more insight into the people and the relationships behind the headlines.

And the actor certainly has an impressive cast of talent to help tell those stories. Fellow Oscar-winner Juliette Binoche (Chocolat) plays the French film editor who began a relationship with Peterson while making the documentary, while Arnold Schwarzenegger’s son Patrick and Game of Thrones’ star Sophie Turner play the convicted killer’s loyal children.

While the Peterson family – just like documentary viewers – were ultimately divided over the writer’s guilt, Firth didn’t form an opinion on that front.

“I tried not to judge,” he says.

“It’s something that was ingrained into all of us as [acting] students, but it’s just not your job.

“I mean as a person you can walk away afterwards and judge all you like if that’s what you want to do or that’s what your instincts are. No, you’ve got to – it’s a subjective job. And what’s interesting about the approach here is it I think deftly avoids taking up a single position.”

The Staircase premieres 5 May on Binge with a triple episode premiere; new episodes weekly

Julia Garner plays con artist Anne Sorokin in Inventing Anna.

TEN TRUE-CRIME TALES TO STREAM RIGHT NOW

From super chic shysters to the brazenly bold baddies, true crime stories are often more convoluted and compelling than anything even the most creative of script writers could cook-up.

These are some too good to be true (crime) dramas to watch:

Inventing Anna, Netflix: Ozark’s Julia Garner is unrecognisable as Russian con artist Anne Sorokin who posed as a German heiress to fleece New York high society out of millions.

Unbelievable, Netflix: Toni Collette and Merritt Wever play the tenacious police officers who caught a serial rapist.

Landscapers, Stan: Like the 1994 movie Heavenly Creatures, this black comedy starring Olivia Colman uses fantasy sequences to give insight into the murderers’ minds.

Underbelly: Vanishing Act, Nine Now: This two-part series follows the events leading up to the disappearance of Melissa Caddick; the woman accused of embezzling $40 million from friends and family.

Eric Bana is mesmerising as John Meehan in Dirty John.

Dirty John, Netflix: A charismatic conman (Eric Bana) will stop at nothing to hold on to his wealthy wife’s fortune. The spin-off followed Betty Broderick (Amanda Peet), the abandoned housewife who gunned down her ex-husband and his new wife.

The Secret, Britbox: A Sunday school teacher and respected dentist (James Nesbitt) embarks on a passionate affair that leads him down a very dark path.

The Girl from Plainville, Stan: Elle Fanning’s portrayal of the girl who urged her boyfriend to kill himself via text messages is beyond uncanny.

Patricia Arquette and Joey King in a scene from The Act.

The Act, Binge: A lonely young woman forced to pretend she is a disabled child by her mother eventually snaps. This remarkable true story starring Patricia Arquette follows the toxic relationship between Gypsy Rose and her mother Dee Dee.

Des, Stan: David Tennant is spinechilling as Dennis Neilson, the murder who earned the nickname the “kindly killer” for the way he politely detailed murdering and dismembering his victims.

A Confession, Britbox: The riveting tale of how one dogged policeman (Martin Freeman) made it his mission to find out what happened to a missing girl.

Originally published as Oscar-winner Colin Firth reveals he wasn’t a true crime fan until The Staircase changed his mind