Jared Leto spent time with psychopaths who had committed "horrendous crimes" to prepare for his role as the Joker.
The 44-year-old actor will take on the role of the supervillain in upcoming superhero movie Suicide Squad and pulled out all the stops to ensure his version of the character was suitably complex.
Talking about his research, he said: "[I met] people that were experts, doctors, psychiatrists that dealt with psychopaths and people who had committed horrendous crimes ... I spent some time with those people themselves, people who have been institutionalised."
Jared remained in character throughout the filming process and was determined his version of the Joker would go in a "different direction" to that of the late Heath Ledger's portrayal in 2008 motion picture The Dark Knight, and Jack Nicholson's version in 1989's Batman.
