The writer of Until I Kill You was concerned about how to keep viewers on Delia’s side

But it is a story that Until I Kill You writes Nick Stevens was aware that he wanted to be proven right – not only to shed light on the tragic crime case, but also to help the public understand the real Delia.

Speaking about his relationship with Delia, Nick Stevens told ITV in a press kit for the series: “When I was working on the scripts I often worried about how on earth we were going to keep the audience on Delia’s side, given her unconventional personality.

“However, when I looked at the dailies from the first day’s filming, I knew we were in safe hands with Anna Maxwell Martin (under the direction of Julia Ford).

“Anna does an extraordinary job of staying true to the spirit of Delia – in all her difficulty – while making her utterly compelling and, crucially, sympathetic.”

He explained: ‘I first met Delia in her literary agent’s office. She was half an hour late for the meeting. She was very excited and wouldn’t look at me. I did my best to reassure her that my intentions were honorable. and that I was actually a reasonable guy, but I don’t think these reassurances made much of an impression on her.

“Over the course of a year, I interviewed Delia many times and little by little she started to trust me. She was very open but also hyper-vigilant. If I got a detail wrong or made an assumption, she disagreed, she would jump me and give me hell. Delia is a complicated person. Aren’t we all?’

He continued, “One of the things I find most baffling about Delia is the fact that her greatest resentment and fiercest anger is not directed at John Sweeney, but at the police and the justice system. Her bitterest tirades are reserved for them.”

“Delia is extraordinary. At 74, she takes ballet classes twice a week, regularly takes long restless walks and travels whenever she can. Because she can’t afford to stay in five-star hotels, she stays in YMCAs and Airbnbs. As she often says with tantalizing pride: ‘I am a traveler, not a tourist.'”

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Stevens also commented on why he felt Delia’s story was important to adapt for a drama: “There aren’t many true crime stories that are told from a woman’s perspective.

“Most officers are men and, tragically, many of the women involved in these types of stories are unable to tell their side of the story. So Delia’s gender was part of the appeal, but more than anything it was her personality.

“The real Delia knows she can be a difficult person, partly because of her own unique wiring, partly because of the PTSD she still suffers from as a result of her time with John Sweeney.”

He continued: ‘Once I got to know Delia – and spoke to some of the police officers who handled her case – I began to realize the extent to which Delia’s personality had negatively affected her dealings with certain key figures in the criminal organization. The legal system whose job it was to protect her. She was not always a compliant or cooperative victim.

“She was often chaotic and angry. I was fascinated by that. Ideally, a victim’s personality should not affect the quality of justice they receive, but that is exactly what happened in Delia’s case.”

Martin leads the series as Delia, while Shaun Evans (Endeavor) stars as John Sweeney. The series follows Delia as she tries to rebuild her life, but also get justice for what Sweeney did to her and his other victims.

Until I Kill You airs on ITV1 and ITVX from Sunday 3 November to Wednesday 6 November at 9pm on ITV1.

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