The Canal Killer: Terrifying Case of John Sweeney

In late 2008, Detective Inspector Steve Smith was part of the Metropolitan Police’s murder investigation team when he received a call about the unsolved murder of a woman called Paula dating back to 2001.

“I picked up the phone and it was a Dutch officer from the fairly newly formed Rotterdam cold case investigation team. He proceeded to ask me some questions, primarily about Paula’s case.”

Paula’s dismembered body had been found in six holdalls submerged in the Regent’s Canal in London. Sadly, her head, hands, and feet were missing; in fact, they’ve never been found, so it became a real challenge to establish any clinical cause of death. The investigation began in earnest the day that she was found here, and a number of lines of inquiry were immediately identified as fairly high priority, but sadly, none of those inquiries really came to anything at all. The killer, it would appear, had been very careful about choosing the time and the site for the deposition of the body parts. With no further lines of inquiry, the murder of Paula went cold until 7 years later when DI Smith received the call from Dutch police. There had been a murder in Holland that had also gone unsolved, but now police had new information which they believed might be helpful in finding the killer in both cases.

“He was then able to tell me, which came as a real shock to me, that they had actually identified the remains of an American national called Melissa Halstead. Melissa had disappeared from Amsterdam in the early part of 1990 and no one had known what had happened to her.”

Melissa’s body had also been dismembered, put in a holdall, and dumped in a canal, but because she was found in Rotterdam, her remains were never identified until now. Through his painstaking inquiries, he had managed to locate a file or a sample of blood which had been taken at the postmortem.

“He then asked for a DNA profile to be formed from the blood sample, which hadn’t been done before, which was duly carried out and a full DNA profile was obtained and they got a match. And the match was with the family of Melissa Halstead.”

The circumstances of her death chillingly echoed those of the unsolved case of Paula. The Dutch detective had a hunch that the two cases may be linked.

“My mind was starting to race because I was thinking this is potentially what you might call a Eureka or a light bulb moment in the investigation. Here we had a body that was dismembered and left in a Rotterdam canal unidentified for well over two decades, and we had the dismembered body recovered from the Regent’s Canal in 2001.”

Looking into Melissa’s past, Dutch detectives had discovered another connection with Paula: a British man that Melissa had previously had a relationship with, a man called John Sweeney.

“What we have is two women. We have one in the Netherlands, we have one in London. Both were known to the same man: Melissa Halstead, who was murdered and dismembered and deposited in a duffel bag effectively and dumped in the Westersingel Canal in Rotterdam. And then we fast forward over 20 years to Paula, also had a relationship with John Sweeney, ended up dismembered, cut into 10 pieces and unceremoniously dumped in the Regent’s Canal over six holdalls. And what it really comes down to is one thing, and the common denominator in both these horrendous and untimely deaths is John Sweeney.”

With the new information linking John Sweeney to the murder in Holland, Steve felt the time was right to reopen the case.

“I was in a positive mood because I immediately thought that we possibly could move this investigation forward, the investigation into the murder of Paula. Following the phone call, I went down the corridor and spoke to my DCI, my detective chief inspector, good friend and colleague Howard Groves. We knew the history behind the investigation in London where the Crown Prosecution decided they weren’t going to… there was insufficient evidence to charge a particular individual. We knew that the Dutch had their half of it, and the same individual. My initial view was, the natural instinct of a detective is, ‘Right, let’s grab this, let’s… we’re going to sort this one out.'”

Steve was happy to be revisiting the case as it had first landed on his desk when he had joined the murder investigation team back in 2004.

“From the material I read, it became very clear that a prime suspect was a man called John Patrick Sweeney. I read the synopsis, if you like, the facts of the case, and the fact that Sweeney was arrested on suspicion of the murder of Paula. Efforts had been made to charge Sweeney on two occasions, but twice the CPS had decided that there was insufficient evidence.”

This case had kept reappearing on Steve’s desk.

“Sometime later, a letter arrived to the investigation team which I opened, and it happened to be from the sister of Paula. And I read the letter and it was… it was quite a moving letter. I took it upon myself to go and meet Irene and the other sisters with a colleague in Liverpool, and we discussed the state of the case effectively, to say that whilst nothing was actively happening, it was a cold case, to never lose hope that the case may be solved. And that was really how we parted company.”

Now, years later in 2008, Steve had a chance to reignite that hope. While no charges had been brought against Sweeney in relation to Paula, he was, however, in prison at this stage.

“John Sweeney was serving a term of imprisonment. In fact, he’d been given a life term in 2002 for the offenses of attempted murder of his then partner. He’d also been found in possession of firearms, so he was serving a life term at this stage. But what it would have meant was that the term of imprisonment he was given, he would have potentially been eligible for parole from 2011. We were acutely aware that Sweeney was likely to be subject of a parole hearing at some point, and with that in mind, we took the view that we had to put a foot on the pedal, still conduct the investigation as meticulously and as professionally as we can. But in the back of our mind, we knew that there was the slight possibility that if we didn’t have sufficient evidence in relation to that case, that he could be given parole and he would be released.”

With this new connection, the Dutch and British teams began a painstaking troll through any police records that involved their prime suspect, John Sweeney. This was the very first time the two European agencies had become involved in a murder inquiry. It was not without its challenges.

“We had to recover all the material from the Melissa Halstead case in the Netherlands, and all that material was in Dutch, so that had to be brought to London, translated. Certain witnesses had to be re-contacted and, where necessary, re-interviewed. Some obviously over the years had forgotten various details, others couldn’t remember what they said originally, so it wasn’t without its problems.”

As they gathered the evidence, they discovered the trail began decades earlier in 1986, when John Sweeney first met American Melissa Halstead, a model at the time. Her family was in the States, but she’d come to London and, in fact, traveled quite extensively.

“That he had killed Melissa, that confession evidence is crucial really to our case because without that we would never have any… any reference or independent reference or evidence that Sweeney had ever admitted to killing Melissa.”

But at the trial, Sweeney refused to comment on the allegations made against him.

“You have been given a chance to explain your side of the story and you have decided to go ‘no comment’. Well, that’s your choice, but that means the jury can say, ‘If I were in your position and I hadn’t done something, then I would want to prove to you I didn’t do X or Y.'”

He did answer some questions; it was more about the artwork on occasion. Sweeney told the court that the artwork he produced—these grotesque pictures of headless corpses and police officers being hung on Christmas trees—was just the product of his warped imagination, something that he’d done when he’d been tripping on LSD. But the links to the crimes were so clear that it was the pictures—the pictures that he produced—which formed the strongest evidence against him in the case.

“He sat there in the dock with, um, earplugs in his ears while, you know, the evidence against him was given. That shows us just how narcissistic and actually quite psychopathic his behavior was, and also how he takes no responsibility for anything he does. I’d been to court quite a few times in my 30-odd years’ service and I’d never seen anybody do that. Just his demeanor in the courtroom and even the jury members, on occasions you could see them just shaking their head.”

The jury took only 10 hours to reach their verdict after a 4-week trial, but Sweeney wouldn’t leave his prison cell at Belmarsh Prison to hear his fate.

“When he was sentenced, he actually refused to come into the dock. He didn’t even have the balls, I hate to use the word, um, to be able to sit and face the music. But that just shows you the nature of the individual. Well, John Sweeney was convicted of the murder of Paula and also perverting the course of justice in that he dismembered the body after death, for which he got 10 years, and he was also convicted of the murder of Melissa Halstead. But what the judge did was, because the murders were so grave, and not forgetting of course that he was already a convicted attempted murderer, the judge actually gave him a whole life sentence, which means he will die in prison. I think the family members and the jury should have at least seen him sit and take his medicine, um, and they… they didn’t get that. But they can still take some solace from the fact that he got life, and life meant he was never going to come out, so he’s no threat to any other female.”

The judge said when he passed sentence on Sweeney that he enjoyed controlling women, and that control extended into deciding whether they lived or died. What makes someone enjoy that sort of control is something we can only imagine.

“Looking back at the case, being happy that I had a team that was professional and I had complete confidence in that they would always do the right thing. I never really had any doubts about convicting him. The only doubts I had were how quick we would do it. To come to this location after all these years and see where the remains of Paula were discovered is… is quite moving in a way, um, but it certainly provides me with a little bit of closure for the whole inquiry. I’m very mindful of the fact that the families maintained their dignity throughout all these years since the death of their loved ones, and I think that’s a fact that should never be overlooked. But yeah, I’m… I’m proud of the work we did and I think, um, it was a job well done.”