A former Met Police detective said the murders of mum Sian Blake and her two sons in Erith will stay with him forever. 

Steve Keogh, who investigated homicide cases in London for 12 years, is lifting the lid on some of his experiences in a new documentary series premiering on TRUE CRIME this Wednesday (March 20). 

The first episode of Secrets of a Murder Detective will focus on a horrific case which shook the Erith community. 

In December 2015, former EastEnders actress Sian Blake and her two sons, eight-year-old Zachary and four-year-old Amon, were murdered by their dad Arthur Simpson-Kent

Weeks later the garden of their family home on Pembroke Road was excavated, unearthing a grave containing their bodies. 

Steve spoke to the News Shopper about the case and how the discovery of the grave was a low point in his career. 

News Shopper: EastEnders actress Sian Blake, 43, and her two young sons, Zachary (left), eight, and four-year-old AmonEastEnders actress Sian Blake, 43, and her two young sons, Zachary (left), eight, and four-year-old Amon (Image: Archive)

‘Soap star’ 

Sian was a successful actor and played the role of Frankie Pierre in 56 episodes of EastEnders in the late-90s. 

She had two sons with Simpson-Kent, a hairdresser she had met on the set of the soap. 

Sian, who had recently been diagnosed with motor neurone disease which left her unable to walk unaided, is said to have been planning on moving on with her life without Simpson. 

But she and her two boys disappeared on December 13, 2015. 

Three days later, after Sian's family contacted the NSPCC concerned for the welfare of the mum and her two sons, police visited Simpson-Kent at home - he told officers Sian and the boys had gone to visit a friend in Cambridge. 

Despite initially being uncooperative, Simpson-Kent then let police into the bungalow. 

When officers returned just a few hours later Simpson-Kent was gone and the house was empty. 

News Shopper: Arthur Simpson-Kent will spend the rest of his life in prison for murdering his partner Sian Blake and his two sonsArthur Simpson-Kent will spend the rest of his life in prison for murdering his partner Sian Blake and his two sons (Image: Archive)

‘We were clinging to hope’ 

It’s very rare for missing person cases to be given to the homicide team, but this case was passed to Steve’s team because of several red flags. 

These included a text sent from Sian’s phone to her sister saying she, Zachary and Amon needed to get away for a while.   

“We are away and I will not be calling or speaking to anyone for a few months,” the message said. 

The text suggested she had gone elsewhere but cell data showed it had been sent from the home address. 

Steve said: “I’ve given up trying to understand exactly why killers do stuff, because you never can, but Simson-Kent was clearly trying to make it seem that Sian was still alive after he murdered her.” 

News Shopper: Steve Keogh was part of the homicide team which investigated the murdersSteve Keogh was part of the homicide team which investigated the murders (Image: AMC Networks)Another red flag was a complete lack of a trail for police to follow.   

“When you investigate a missing person, one of the things you look for is signs of life. Anything in our day to day that leads a trail – be that seeing people, communications, credit card use. There was none of that,” Steve said. 

“Immediately you start to think it doesn’t look good. In our minds we thought even if the worst has happened to Sian, maybe he put the boys somewhere, maybe he got some family members to look after them. We were clinging to that.” 

‘The low point of my career’ 

These hopes were dashed when a closer look inside the house revealed some walls had been painted to hide bloodstains. 

Then on January 5, 2016, the back garden of the house was excavated, revealing a grave with Sian and her two boys inside. 

News Shopper: The house in Pembroke Road, ErithThe house in Pembroke Road, Erith (Image: Archive)“I’ve got to be honest that was probably the low point of my career,” Steve said. 

“I’ve dealt with a hundred plus murders, I wouldn’t want to put a figure on how many dead bodies I’ve seen, but the ones that will always remain with me are the children.  

“As a father seeing children coming to harm. Some murders you can get your head around them and see why they’ve happened, if someone’s got caught up in emotion but to harm children is something you can never get your head around.” 

Steve said he still remembers to look on his colleagues’ faces when they returned from the post mortem examinations which revealed they had all suffered serious head injuries before being stabbed in the neck. 

Zachary had defensive injuries, indicating that the last thing he saw was his dad attacking him. 

“The fact that Zachary would have been aware of them just all adds to the barbaric tragic case that will always sit with me,” Steve said. 

News Shopper: Zachary, 8, and Amon, 4Zachary, 8, and Amon, 4 (Image: Archive)

'Determination to get justice’ 

“I remember there was a real sense of determination on the team that while this is what we feared would be the worst-case scenario, we need to do what we can to get hold of Simpson-Kent as soon as possible and get him back,” Steve said. 

“When you investigate murders you see some of the worst things, but because of our job it feels like you can do something about it. You’re not feeling helpless and there’s a steely determination that we’re going to do this.” 

Simpson-Kent had taken a bus to Glasgow then flown to Ghana via Amsterdam, investigators established. 

An initial worry for Steve was that the killer might take his own life while abroad. 

It fell on Steve to organise the extradition of Simpson-Kent after he was tracked down to a beach in Ghana where he was sipping a coconut. 

He described this as a hugely challenging process and it wasn’t until a month after his arrest that he was flown to the UK. 

Simpson-Kent later pleaded guilty to the three murders and was given a whole life sentence. 

Despite this, Simpson-Kent has never revealed why he murder Sian, Zachary and Amon. 

News Shopper: Arthur Simpson-Kent Arthur Simpson-Kent (Image: Archive)

‘Secrets of a Murder Detective’ 

Secrets of a Murder Detective sees Steve in conversation with a number of leading officers on some of London’s biggest murder cases as they share memories of the investigations. 

Steve said: “Most of the true crime shows I see are slightly superficial in that they tell the story but there’s no insight into what the police were doing and why they were doing it. 

“What you would often see in a high-profile case is an officer at the beginning making an appeal for witnesses or information, and the next time you see them they might be outside the Old Bailey thanking the jury and reading a statement for the family. 

“But in between so much has gone on and quite often it’s a real uphill battle to get to that stage. So for me I wanted to give viewers a glimpse behind that curtain to see how difficult it is and the determination police officers show.” 

The first episode premieres on TRUE CRIME at 10pm on Wednesday (March 20) and will also be available to stream on Watch Free UK. 

It will reveal the inside story of how Simpson-Kent was brought to justice.