HOW do you know if someone is a psychopath? Well criminal psychologist Dr Robert Hare actually made a handy list for you to check, and one thing’s for sure, everyone’s favourite female assassin, Villanelle, ticks every box.

Author of the Killing Eve series, the mild, soft spoken Luke Jennings, hardly seems like the type to think up countless horrific (yet ever inventive) deaths. But here he was, discussing murder, madness and his latest novel in the series Killing Eve: No Tomorrow with BBC Newcastle’s Adrian Pitches on stage at the Queen’s Hall.

“I was interested in what would make someone choose to work as a professional assassin, and that was how the series came to be,” Luke said. “If you could live how and where you want, but every you often you have to kill someone, to what kind of person would that be a good deal? The character of Villanelle arouse from these questions then, but she takes it one step further, she gets a thrill out of killing, and doing it well.”

It is a combination of scientific traits and characteristics of a psychopath, combined with inspiration from famous real-life female assassins’s such as Idoia Lopez Riano, nicknamed La Tigresa, who killed 26 police officers in Spain during her career, which brings Villanelle’s character to life, Luke said.

“She sees the world around her in a completely different way,” he explained. “One where death becomes part of the everyday, even comical for her at times, because she has absolutely no empathy.

“Coming originally from this incredibly grim, hugely improvised background in Russia,” Luke said. “To living a life of luxury in France, with access to unlimited money and designer goods – its this huge, unimaginable leap which she can never return from.”

Contrasting the villainous Villanelle then is the chaotic, clumsy, intuitive and loveable MI5 officer Eve Polastri.

“Eve is everybody,” Luke said. “She’s the one who burns the toast, and is always running late for things. She makes the decisions which most of us would make, and in that way we can all relate in some way to Eve in a way which most of us can’t relate to Villanelle.”

On the question ‘why women?’, Luke’s answer was simply ‘why not?, explaining that whilst many of us have seen the male assassin on big and small screens for decades, but the role of the female assassin is less known.

When questioned on the methods to his madness, which was how do you think of the different ways to kill your characters? Luke explained that he thinks of each murder as a puzzle.

“In the modern age, with technology such as CCTV and facial recognition, you have to plot how to get away with murder very carefully.” He added: “Each kill therefore becomes a intellectual problem to solve, for both me writing it, and Villanelle acting it out.”

Of course, the talk wouldn’t be complete without mentioning the hit TV show, and Luke did not shy away from discussing all the details, including how his self-published e-novel became the screen sensation.

“Making a self-published novel a success is tricky, because you are putting your novel into a ocean of not always great work,” he said. “Therefore you have to make sure that your work gets to the right people, and that they actually read it.”

But even after BBC America decided to option Killing Eve for television, the series came with controversy.

One European country (which Luke tactfully left unnamed) was reluctant to air the series on the basis that they felt an action series with two lead women, “especially an Asian woman” would fail to get views.

“We told them at the time that they would rethink that decision, because we knew that we had something different,” said Luke. “And they did once they’d seen its success in other countries.

“I’m so pleased that it has connected with readers and audiences of all ages, genders, sexualities and nationalities. It’s also amazing to know people are brought together through their shared loved of the series.”