Until I Kill You true story: What happened to the real Delia Balmer?

The four-part series stars Anna Maxwell Martin as Delia Balmer, a woman who survived a relationship with John Sweeney.

The series is inspired by Delia’s 2017 memoir, Living with a Serial Killer, and is accompanied by the new documentary, which digs deep into the timeline of Sweeney's grisly actions and his pursuit of Balmer.

Wondering what exactly happened to Delia Balmer and where she is now? Read on to find out everything you need to know about the subject of the new ITV drama.

Until I Kill You true story: What happened to Delia Balmer?

Balmer was born in Canada and grew up in America, having dreams of being a dancer one day. With a love of travel, she left behind her family in Texas and started working as a nurse in London.

Leading a fairly solitary life, Balmer went to a pub one evening as they had a good jukebox and that was where John Sweeney approached her at the bar, offering to buy her a drink.

Sweeney appeared to be a charismatic carpenter from Merseyside and quickly, the pair bonded over their carefree spirits and love of travel. Sweeney told Balmer about his travels to Europe for his work and although Balmer wasn't looking for a relationship, things quickly developed for the pair.

Balmer took Sweeney to Texas to meet her family but her parents didn't like him. "He did not fit in", Balmer explains in Until I Kill You: The Real Story.

"I just figured my sister knew better," Balmer's brother Stewart also said in the documentary, going on to describe an instance where he asked Sweeney whether he'd ever killed anyone and not receiving a straightforward 'yes' or 'no'.

But back home in the UK, Sweeney got more controlling over Balmer, criticising her appearance and ways she'd spend her free time. Balmer said she argued with Sweeney and told him to leave, going into her bedroom to go to sleep.

He burst into her room and tied her to her bed, he then reportedly pulled out a knife and gun he kept hidden and interrogated her about ex-boyfriends.

It was there that Balmer said Sweeney confessed to killing ex-girlfriend Melissa Halstead, saying that he found Halstead with two other men and he shot them all, cut up their bodies and threw them in the canal in Amsterdam.

Sweeney assaulted Balmer multiple times and then, after a week imprisoned in her own home, he let her go and disappeared. For months afterwards, Balmer lived in fear that Sweeney would attack her again and she tried to tell the police about what Sweeney had confessed to her.

Months later, she came home to find Sweeney hiding out in her flat. Because she was supposed to be at a friend's party and the very same friend knew of Sweeney's abusive behaviour, Balmer's friend alerted the police. The police eventually arrived at Balmer's flat and Sweeney ordered her to make them go away and tell them everything was alright. Instead, Balmer ran to safety and the police finally arrested Sweeney.

After searching his possessions, the police found a hacksaw blade, gloves, rope, tarpaulin and tape. Sweeney was charged with false imprisonment and actual bodily harm but was shockingly released on bail soon after, meaning Balmer was at risk.

She wasn't informed of his release immediately and on 22nd December 1994, after finishing her last nursing shift for the year, Balmer walked up to her home to see Sweeney approaching her in the dark.

He attacked her with an axe and a knife – cutting off one of her fingers in the process – but a neighbour thankfully intervened and Sweeney fled.

After the attack, and with Sweeney on the run under multiple aliases, Balmer spent months in hospital recovering from her extensive injuries. She went back to university and made some new friends, seeking to rebuild her life, but she would later be contacted by the police to come face-to-face with Sweeney once again.

Where is Delia Balmer now?

Delia now works as a therapeutic masseuse, according to The Mirror.

Speaking to ITV ahead of the series, Delia said she is still left with a feeling of anger following the whole ordeal.

She explained: "When I wrote my original story, I included every detail of what happened. When it came to the final attack on the doorstep, I edited it over and over again, wanting everything to read precisely as it had happened.

"My concern has always been to get the truth out by whatever means. I remain an angry person. Sweeney was let out on bail. The police gave me insufficient protection before his final assault. Later, I was forced to go to court to be further traumatised by the system."

What happened to Melissa Halstead and Paula Fields?

Four years prior to meeting Delia, Sweeney had been in a relationship with American model Melissa Halstead, who had mysteriously disappeared.

Halstead had arrived in the UK in 1986, met Sweeney, then moved in together. Because of her overdue stay in the UK, Halstead was deemed to be an "overstayer" but paired with the fact that Sweeney had grown increasingly violent, she eventually ran away.

Sweeney tracked her down to Vienna and was arrested there in 1988 for attacking her with a hammer. Despite his violent act, Halstead bailed him out of prison but then fled by herself to Amsterdam in 1990. Shortly after, Sweeney found her and the pair eventually reconciled, moving in together.

The following year, Halstead was seen in one last image with Sweeney, but was never seen again. Due to the nature of her job and travels, it took a while before her family realised something was wrong and that she was missing. With no body, though, her missing person's case ground to a halt.

In Rotterdam in 1990, the dismembered remains of a white female were then found in the Westersingel canal, with the head and hands having been removed. Because there were no identifying marks on the body, the case was effectively closed. Halstead's body was only identified in 2008 after Dutch detectives carried out a cold case review and matched familial DNA.

In February 2021, two boys found a holdall in London's Regent's Canal and in it, a woman's dismembered body who was later identified as Paula Fields. In total, 10 body parts were found in six holdalls across the canal.

Fields had moved from Liverpool to London and found life difficult in the capital city as a working single mother of three. Four weeks after Fields's body was found, Sweeney was arrested, and although there was no evidence to link him to Fields initially, he was wanted for Balmer's attack six years prior.

The police also found gruesome artwork made by Sweeney.

Because of the lack of evidence for Fields's murder, the police convinced Balmer to take the stand in court against Sweeney for his attack on her in 1994.

Balmer eventually agreed to stand in the witness box, but had a major outburst that prompted the court to take a recess.

After speaking to her liaison police officer, Balmer gave evidence about her ordeal and Sweeney was eventually sentenced to four life sentences for his brutal attack on her.

While imprisoned, he was also questioned about Fields and the police subsequently found lots more artwork (300 pieces) depicting more gruesome scenes, poems and several weapons.

The police asked Balmer to testify again but this time, she refused to do so because of the impact of doing so previously. Even so, in 2011, Sweeney was found guilty of the murders of both Fields and Halstead.

During the trial, the jury heard how Sweeney had written on the back of a scratch card: "Poor old Melissa, chopped her up in bits, food to feed the fish, Amsterdam was the pits."

Another drawing depicted a gravestone with the words: "RIP Melissa Halstead."

Already serving a life sentence for the attempted murder of Balmer, Sweeney's 2011 sentencing was done at the Old Bailey in his absence, as he refused to leave his cell.

Judge Mr Justice Saunders said at the time: "These were terrible, wicked crimes. The heads of the victims having been removed, it is impossible to be certain how they were killed. The mutilation of the bodies is a serious aggravating feature of the murders.

"Not only does it reveal the cold-blooded nature of the killer, but it has added greatly to the distress of the families to know that parts of their loved ones have never been recovered."

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

Check out more of our Drama coverage or visit our TV Guide and Streaming Guide to find out what's on. For more from the biggest stars in TV, listen to The Radio Times Podcast.