To go "method" some actors lose weight or work part-time at the jobs held by their characters. For Jamie Dornan, he took it a step further – following a woman on the subway as background research for his role as psychotic serial killer Paul Spector on Netflix crime thriller The Fall.
Much like his trip to a sex dungeon to prepare for his role in Fifty Shades of Grey, the Irish actor went to even crazier extremes to get into the mindset of a sadistic murderer.
Jamie Dornan stalked a woman as research to play a serial killer
LOS ANGELES, CA - MARCH 29: Actor Jamie Dornan speaks during Variety Studio Actors on Actors presented by Autograph Collection Hotels on March 29, 2015 in Los Angeles, California. on March 29, 2015 in Los Angeles, California. (Photo by Joe Scarnici/Getty Images for Variety)
LONDON, ENGLAND - SEPTEMBER 02: Jamie Dornan attends the GQ men of the year awards at The Royal Opera House on September 2, 2014 in London, England. (Photo by Ben Pruchnie/FilmMagic)
LONDON, ENGLAND - SEPTEMBER 02: Amelia Warner (L) and Jamie Dornan attend the GQ Men Of The Year awards in association with Hugo Boss at The Royal Opera House on September 2, 2014 in London, England. (Photo by David M. Benett/Getty Images)
LOS ANGELES, CA - SEPTEMBER 20: Jamie Dornan seen at LAX on September 20, 2014 in Los Angeles, California. (Photo by GVK/Bauer-Griffin/GC Images)
LONDON, ENGLAND - MAY 19: Jamie Dornan seen visiting a gym in Notting Hill on May 19, 2014 in London, England. (Photo by Neil P. Mockford/GC Images)
LONDON, ENGLAND - MAY 18: Jamie Dornan (L) and Amelia Warner attend the Arqiva British Academy Television Awards at Theatre Royal on May 18, 2014 in London, England. (Photo by Stuart C. Wilson/Getty Images)
DUBLIN, IRELAND - APRIL 05: Jamie Dornan attends the Irish Film And Television Awards on April 5, 2014 in Dublin, Ireland. (Photo by Phillip Massey/WireImage)
LONDON, ENGLAND - SEPTEMBER 05: Jamie Dornan attends the '9 Countries, 9 men, 1 Winner' Calvin Klein Photocall at House of Fraser, Oxford Street on September 5, 2009 in London, England. (Photo by Dave M. Benett/Getty Images)
JAMIE DORNAN at the Moet & Chandon Tribute to Cinema party held at the Big Sky Studios, Brewery Road, London N7 on 24th March 2009. - Job: 64511 Ref: DON - (Photo by Dominic O'Neill/Photoshot/Getty Images)
LONDON - APRIL 16: Actor Jamie Dornan arrives at the launch party for film 'Beyond The Rave' at Shoreditch House on April 16, 2008 in London, England. The film is the first Hammer horror in 30 years and will be broadcast exclusively on social network internet site MySpace. (Photo by Dave Hogan/Getty Images)
Rob Brydon, Jamie Dornan and James Purefoy (Photo by Nick Harvey/WireImage)
LONDON - MAY 15: (EMBARGOED FOR PUBLICATION IN UK TABLOID NEWSPAPERS UNTIL 48 HOURS AFTER CREATE DATE AND TIME) (L-R) Rob Brydon, Jamie Dornan and James Purefoy attend a charity evening in aid of CLIC Sargent, at the Sanderson Hotel on May 15, 2007 in London, England. (Photo by Dave M. Benett/Getty Images)
Jamie Dornan during The British Fashion Awards 2006 at V & A in London, United Kingdom. (Photo by Fred Duval/FilmMagic)
Jamie Dornan during Columbia Pictures Presents the New York Film Festival Screening of 'Marie Antoinette' at Alice Tully Hall in New York, New York, United States. (Photo by E. Charbonneau/WireImage for Sony Pictures-Los Angeles)
Rose Byrne and Jamie Dornan during Columbia Pictures Presents the New York Film Festival Screening of 'Marie Antoinette' at Alice Tully Hall in New York, New York, United States. (Photo by E. Charbonneau/WireImage for Sony Pictures-Los Angeles)
Jamie Dornan in the Virgin Mobile Louder Lounge at the V Festival at the Chelmsford in United Kingdom. (Photo by Jon Furniss/WireImage)
"The first series, I did do a couple of things to try to get inside [his mind]. On the tube, which is our underground system-" Dornan said before stopping himself, fearful that he might face legal repercussions for his intense preparation. "Can we get arrested for this? Hold on ... this is a really bad reveal: I, like, followed a woman off the train one day to see what it felt like to pursue someone like that."
Dornan detailed his experiment, explaining that he kept his distance from the woman until she reached her exit, and then followed her clandestinely for a few blocks in order to feel just a bit of what his character feels when stalking a victim.
"It felt kind of exciting, in a really sort of dirty way," Dornan revealed. "I'm sort of not proud of myself. But I do honestly think I learned something from it, because I've obviously never done any of that. It was intriguing and interesting to enter that process of 'what are you following her for?' and 'what are you trying to find out?'"
In The Fall, Dornan's Spector is a father, a husband, and a lunatic who revels in tying up women before murdering them. The series follows Spector's life of crime and the investigation conducted by Detective Superintendent Stella Gibson (Gillian Anderson) who is trying to catch him.