I investigated many murders during my career, more than I can count. But very few sent ripples much further than the communities in which they took place. Occasionally, though, I found myself at the centre of the country’s biggest news story. When your investigation dominates the headlines, the pressure is unreal. Every decision is scrutinised. Every delay criticised. Every mistake magnified. That attention ratchets up another level when a killer is identified and the manhunt becomes public. Suddenly, you’re not just trying to solve a murder and bring a killer to justice. You’re in a very public race against time. Every hour that passes without an arrest, fuels more speculation, more criticism and more questions about whether you’ll ever catch the person responsible. But it isn’t the criticism itself that keeps you awake at night. Throughout my career, the people I always felt most accountable to weren’t senior officers, politicians or journalists. They were the victim’s family. They had placed their trust in us at the darkest time of their lives. What you fear is that the constant public scrutiny begins to erode that trust. That they start to wonder whether the criticism they’re reading or hearing might be true. If that relationship begins to suffer, that’s when the pressure really hits. As I read about Walter Dew’s hunt for Dr Crippen, I couldn’t help wondering whether he felt that same burden of responsibility. The more I learned about his investigation, the greater the sense of kinship I felt with him. More than a century after Dew pursued Crippen, I found myself leading an international manhunt under remarkably similar circumstances. A celebrity reported missing. Murdered by her partner. The suspect fled abroad before the full picture emerged. The most heartbreaking difference was that my investigation also involved her two young sons. In almost every other aspect, the parallels were remarkable. In January 1910, American-born music hall singer, Cora Crippen, disappeared. A friend raised her concerns with the police, but initially not much appeared to have been done to locate her. But in July of that year, after the intervention of a police superintendent who had been contacted by friends of Cora, Chief Inspector Walter Dew visited the marital home and spoke with Cora’s husband, Dr Hawley Crippen. Just over a century later, concerns around the controlling behaviour by the partner of former Eastenders actress, Sian Blake, were raised by her family. As a result, police officers visited her home and spoke with her partner, Arthur Simpson-Kent. Both men gave seemingly plausible explanations as to their partner’s whereabouts. Crippen told Dew that Cora had left him for another man and travelled to America. Simpson-Kent said Sian had taken their two sons to visit a friend in Cambridge. Both homes were searched. Neither search revealed evidence to raise suspicion that either woman had come to any harm. For Walter Dew, verifying Cora’s whereabouts would have been extremely difficult, given the technology available in 1910. In Sian’s case, nobody could contact her after a text message was sent to her sister purportedly from Sian explaining that she needed to get away from everything. Sian was then officially reported as a missing person, along with her two sons, Zachary aged 8 and Amon aged 4. An investigation that was initially conducted by local police. Several weeks later, in the first week of January, her case was referred to us as the on-call murder team. A local superintendent feared serious harm may have come to them. Sadly, he was proven to be right. As detectives, you are taught to continually question the narrative. To never become fixed on one theory. What seems certain one day can change completely the next. Although Dew had accepted the explanation given to him, something about the story seemed to bother him. However, when he returned to make further enquiries with Crippen, the man had vanished. Whatever doubts Dew had been harbouring were now being confirmed by Crippen’s disappearance. After all, if he had been telling the truth, why would he run? Fearing what may have happened to Cora, he ordered a thorough search of the home, which led to a gruesome discovery. Below the brick floor of the basement lay the dismembered remains of a woman. Dew was convinced these were Cora Crippen. When Sian’s case came into my team, none of us believed we were being handed a simple missing persons case. One of the biggest alarm bells for me was the fact Sian had advanced motor neurone disease. She could just about care for herself, let alone the two boys. Added to this, by then, Simpson-Kent had disappeared, with all attempts to contact him having failed. Colleagues revisited the family home, intent on a more thorough search. They quickly discovered evidence of a violent incident, with substantial traces of blood having been painted over, in an apparent attempt to hide a crime. Within a few days of us taking over the investigation, it turned into something we all dreaded would come to pass. Buried in the back garden, we found the bodies of Sian, Zachary and Amon. And it was apparent that they had each died in the most brutal of ways. Both cases were now murder investigations. Both suspects had fled. And both had a head start on the investigators. When you investigate murders, you can become almost numb to the things you see. In many ways you have to. As awful as they are, you have a job to do, and if you got caught up in your own emotions, you won’t be doing that job to the best of your ability. That doesn’t mean, though, you can switch off completely. There are times when it’s impossible not to be affected by what you’re dealing with. When I received that phone call from the scene, it was one of the low points of my career. As much as I feared what may have happened to them, there is always that hope that you’re wrong. That they are alive somewhere. The blood at the house made that unlikely, but there was always the chance the children were alive. To have those hopes taken away was heartbreaking. As a parent, and simply as a human being, I felt sadness, anger and disbelief. But rather than let those emotions negatively affect me, I used them as extra motivation to ensure that I, and we as a team, did all we could to find this man and make sure he faced justice. I do wonder how finding that body affected Dew. As much as he may have suspected Cora had come to harm, I can’t help but think he hoped he was wrong. Did discovering her remains in such a gruesome condition stay with him? We’ll never know. In his memoirs Dew wrote mainly about what he did rather than his emotions. But I do know what came next, because I lived it myself. Once the bodies are found and the suspect has disappeared, everything changes. This is murder. And the person responsible is doing everything they can to escape you. To avoid arrest, to avoid a trial and, ultimately, to avoid justice. Manhunts are part of the job. Suspects run all the time. After all, if they’re caught, they face many years in prison. In Walter Dew’s time, they faced execution. That motivation can add to a person’s determination not to be caught. As detectives, you develop ways of finding people who run. I took pride in the fact that, sooner or later, I always found them. It was that experience that resulted in me leading the hunt for Simpson-Kent. After what he had done to his family, whatever determination he had to get away was matched by mine to ensure he didn’t. What I hadn’t experienced before was leading a manhunt under such intense public scrutiny. Dew may well have felt the same. Was that a good thing or a bad thing? For me, it proved to be very much a double-edged sword. There’s a famous scene in the film The Fugitive where Tommy Lee Jones explains how far an escaped prisoner could have travelled, using that to calculate the search area. Now, that’s all well and good when you’re minutes behind them. But what if they have a day’s head start, as was the case for Dew, or several weeks, as it was for me. Where do you begin in finding them? Well, you firstly need to learn as much as you can about their lives. You build as full a picture as you can about their habits, the places they frequent, where they work or socialise. Who they are friends with. Who they regularly have contact with. Who in their circle is most likely to help them. My advantage over Walter Dew was the footprints we all leave behind us today. Phones. Cars. Bank cards. Travel cards. Loyalty cards. Social media. CCTV. Travel bookings. Passport usage. Any number of interactions we make every day. When I pulled all this together for Simpson-Kent, I got an answer I didn’t want. He had left the UK, travelling by plane to Amsterdam and then onto the country of his birth, Ghana. As confident as I was in my abilities to catch a fleeing suspect, factoring in a different continent, I knew that was going to make things a whole lot harder. Not only that, why Ghana? Suspects on the run will often gravitate to areas they’re familiar with, as it gives more connections to hide them or just that sense of feeling safer. But Simpson-Kent left there as a very young child, so he didn’t know the country and, as far as I could tell, had very few relatives there. One thing that was always on my mind, having killed his family, why didn’t he do what many killers do in these circumstances, and go on to take their own lives? If he did have suicidal thoughts, was returning to where he was born some kind of poetic ending? As much as I hated him for what he’d done, I wanted justice for Sian and the boys. Him killing himself wouldn’t achieve that. Or was it simply a place he knew and would give him the best chance of evading us? Either way, I knew I had to locate him as soon as humanly possible. In 1910, Walter Dew had a very different task ahead of him.