Until I Kill You writer worried about how to keep viewers on Delia’s side

But it's a story that Until I Kill You writer Nick Stevens was conscious of getting right – not only to shine a light on the tragic true crime case, but to also help the audience understand the real-life Delia.

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

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

"Anna does such as extraordinary job of staying true to the spirit of Delia – in all her difficult-ness – while at the same time making her utterly compelling and, crucially, sympathetic.”

He explained: "I first met Delia in the office of her literary agent. She was half an hour late to the meeting. She was very agitated and wouldn’t look at me. I did my best to reassure her that my intentions were honourable and that I was basically a reasonable bloke, but I don’t think these reassurances made much 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 did not agree with, she would pounce 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 most ferocious anger is directed not at John Sweeney, but at the police and the court system. Her bitterest tirades are reserved for them."

"Delia is extraordinary. At 74 she does ballet classes twice a week, regularly goes out for long restless walks, and travels whenever she can. Unable to afford to stay in 5-star hotels, she stays in YMCAs and Airbnbs. As she often says with tetchy pride, 'I’m a traveller not a tourist.'"

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Also speaking about why he felt Delia's story was an important one to adapt for a drama, Stevens said: "There aren’t many true crime stories out there which are told from a woman’s perspective.

"Most of the cops are male and, tragically, many of the women involved in such stories are not alive to tell their side of the story. So, Delia’s gender was part of the appeal, but mostly, it was her personality.

"The real Delia knows she can be a difficult person, partly due to her own unique wiring, partly due to the PTSD she still suffers from as a consequence of her time with John Sweeney."

He went on: "Once I’d got to know Delia – and spoken to some of the police officers who handled her case – I began to realise the extent to which Delia’s personality had negatively impacted on her dealings with certain key individuals in the Criminal Justice 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 the justice they receive, but that is exactly what happened in Delia’s case."

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

Until I Kill You will air on ITV1 and ITVX from Sunday 3rd November to Wednesday 6th November at 9pm on ITV1.

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