Paul Dano researched "serial killers" for his version of The Riddler.

Paul Dano did his research for the role

Paul Dano did his research for the role

The 37-year-old actor plays the iconic comic book villain in filmmaker Matt Reeves' blockbuster 'The Batman', and the director has opened up about using the Zodiak Killer as inspiration for the character.

Paul told SFX magazine: "That was a reference point Matt gave me, and I read quite a bit about serial killers in general, which wasn't light reading.

"I found that, actually, it was a little challenging to go to the coffee shop and read. I needed more friendly surroundings to read that stuff.

"But I actually found, then, going to Matt's script, that that reference only took me so far. On behalf of the character, I felt like his sense of purpose and intention was much greater and deeper."

Dano noted the foundation for his character was rooted in the script penned by Matt Reeves and Peter Craig - while Mattson Tomlin also contributed.

He explained: “There’s a reason why Batman, and why Gotham, has resonated for so long and why it can keep being reinterpreted. But it really starts with something that’s not general. And luckily, this script was highly specific.

"The point of view was really clear and from there, we hopefully build our versions of these characters.

"So, it’s not coming from some familiarised idea of what the Riddler might be. It's coming from the character on the page and investigating who he is and why he’s there.”

On the development of his character, the actor made sure to delve into who Edward Nygma - the Riddler himself - is as a person.

He asked himself: “What’s the nature and nurture elements of this? How did he get to this place?

"That was a really big part of the development of the character for me and, luckily, what Matt wanted out of this was something that was not only epic in scope and lived up to Gotham and the comics and the archetype, but something that was really grounded and deeply personal and deeply emotional."