It started in a pub in Camden. Late 1991. Delia Balmer, a nurse at the Royal Free Hospital, met a man named John Sweeney. He was a carpenter, a bit of a bohemian, and he liked to draw. Honestly, he seemed fine at first. Maybe a little scruffy, but caring.
But things went south. Fast.
The story of John Sweeney and Delia Balmer isn't just another true crime headline you scroll past. It’s a messy, infuriating, and deeply disturbing look at how a serial killer hid in plain sight while the people supposed to protect the public essentially looked the other way. You might have seen the ITV drama Until I Kill You starring Anna Maxwell Martin and Shaun Evans. It’s a tough watch because the reality was even tougher.
The Red Flags Nobody Saw (Or Wanted to See)
Sweeney wasn't just "moody." He was a ticking time bomb with a portfolio of nightmares. He had this habit of sketching—obsessive, violent drawings that most people would find alarming. Delia saw them. She lived with them.
Over the course of three years, the relationship turned into a prison. Sweeney became controlling, then violent. He held her hostage. He tied her to the bed. He tortured her. It wasn't a secret, either; Delia went to the police. She told them he was dangerous. She told them he had confessed to killing his previous girlfriend, Melissa Halstead.
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What did the system do? They granted him bail.
The Night Everything Shattered
In December 1994, the inevitable happened. Since Sweeney was out on bail for a previous assault on Delia, he was free to finish what he started. He waited for her outside her home with an axe and a knife.
It was a bloodbath.
He hacked at her, nearly severing her finger, wounding her chest, and leaving her for dead. If it wasn't for a neighbor, a guy who actually intervened with a baseball bat, Delia Balmer wouldn't be here to tell the story. Sweeney fled. He didn't just go around the corner; he vanished into the woodwork of Europe and London for six years.
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While Delia was left to rebuild her body and her mind, Sweeney was busy.
The Victims We Know About
- Melissa Halstead: An American photographer and model. Her torso was found in a canal in Rotterdam back in 1990. It took nearly twenty years to officially identify her through DNA. Sweeney had literal poems about her: "Poor old Melissa, chopped her up in bits."
- Paula Fields: A mother of three. She met Sweeney in 2000 while he was still "on the run" from the axe attack on Delia. Her remains were found in six holdalls in Regent’s Canal in 2001.
Why This Case is a Total Failure of Justice
The most sickening part? Sweeney had a history of violence long before he even met Delia. In 1982, a man named John Sweeney (different guy, same name, often confused in early reports but a separate case of domestic tragedy) killed actress Dominique Dunne. While that John Sweeney isn't the "Canal Killer," the fact that our John Sweeney was able to skip across borders and maintain a "charming" persona despite multiple reports is what haunts the Delia Balmer case.
The police had his drawings. They had a confession he made to Delia. They had a woman pleading for her life. And yet, he was allowed to walk out of a station and go find another victim.
Sweeney was finally caught in 2001, but only for the attack on Delia and for possessing weapons. It took until 2011—ten years later—to finally convict him for the murders of Melissa and Paula. He’s currently serving a whole-life tariff. Basically, he’s never coming out.
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Survival is Not a Straight Line
Delia Balmer’s life changed forever. She wrote her book, Living with a Serial Killer (later re-released as Until I Kill You), because she was sick of how the media and the courts treated her. She wasn't a "perfect victim." She was angry. She was traumatized. She felt—and still feels—let down by the Metropolitan Police.
Today, she does therapeutic massage. She takes ballet classes. She travels. But you don't just "get over" having an axe-wielding serial killer as an ex-boyfriend. The physical scars are there, and the psychological ones are deeper.
Actionable Takeaways for True Crime Followers
If you're following this case or others like it, there are a few things to keep in mind regarding safety and advocacy:
- Trust the Intuition: In almost every account Delia gives, there was a moment where the "vibe" shifted. If someone shows you who they are through violent "art" or "jokes" about exes, believe them.
- Document Everything: If you or someone you know is in a volatile situation, digital footprints, photos of injuries, and contemporaneous notes are vital. The legal system often fails, but having a paper trail is your best weapon.
- Support Victim Advocacy: This case is a prime example of why police reform regarding domestic violence and bail conditions is non-negotiable. Supporting organizations like Refuge or Women's Aid helps keep these issues in the spotlight.
The story of John Sweeney and Delia Balmer is a reminder that monsters don't always look like monsters. Sometimes they just look like a scruffy carpenter in a pub.
To better understand the legal nuances of these types of cold cases, you should look into how Eurojust now handles cross-border DNA matching, which was the turning point that finally linked Sweeney to the Rotterdam murder decades later.