The horrific and shocking details of Sadie Hartley's death were revealed in a behind-the-scenes ITV documentary on Thursday night (September 2).
The Murder of Sadie Hartley unveiled the meticulous police work that led to the arrest of Chester killers Sarah Williams and Katrina Walsh.
Williams, of Treborth Road in Blacon, was ordered to serve a minimum of 30 years in prison, while 55-year-old Walsh, of Hare Lane in Guilden Sutton, was also jailed for life with a minimum term of 25 years last month for the ‘evil’ killing of innocent Mrs Hartley.
A jury found she had helped her pal Sarah Williams in her plot to ‘eliminate’ the popular mum-of-two after Williams had an affair with her partner Ian Johnston.
Here are 10 things we learnt from the documentary.
1. How Williams tried to forensically clean her home
Sarah Williams was arrested days after Sadie’s brutal murder. Detectives had hoped to find a wealth of forensic evidence but instead found her home had been scrubbed ‘top to bottom’ with bleach. However Williams missed one vital spot which was described as a ‘chink of light’ in the case.
A detective describes how a search of the her home initially drew a blank, until they found a trace of Sadie Hartley’s blood in the bathroom.
It’s this that became a key point during questioning - when Williams failed to explain why the victim’s DNA was in her home.
2. How Walsh tried to cover her tracks with manure
Katrina Walsh took police to the field where the murder weapons - a knife and Taser - were hidden.
She told them: “I put the horse poo on top.”
At the scene, a barb from a stun gun was recovered, as well as a stun gun missing a ‘barb’.
A car key - and eventually the knife used in the murder itself - were also found too.
3. How Williams ‘lost her cool’ as police stepped up the pressure on her
Williams was ‘cool, calm and collected’ throughout initial questioning, detectives said.
She initially appeared ‘unfazed’ by being in custody.
Officers were surprised by her attitude despite being told she was under suspicion of murder.
Her cool did break, they said, when officers were able to place her and Walsh in Helmshore before the murder thanks to her mobile phone.
In her fourth interview, she went ‘into her shell’ and started answering ‘no comment’ to all questions.
Clad in a blue police blanket, Sarah Williams was later seen standing emotionless at the custody desk as she was formally charged, before being taken back into her cell.
4. How Katrina Walsh’s ‘bad memory’ claims were exposed as a lie
On arrest, Katrina Walsh claimed to have short term memory loss - and forget things in ‘three sleeps’.
She said she had a ‘feeling’ that her friend was a psychopath, but it took time before the truth unravelled.
Officers described her as being in ‘a trance’ as she began to reveal the details of the case.
She told officers she was sure Williams had murdered Sadie - but claimed she “wants to frame me for it, or kill me’.
But her memory claims were thrown into doubt when her diaries were discovered, in which she writes lucidly about the past and events which happened weeks before.
The diary also first refers to a plot to murder Sadie 18 months before the killing itself.
As one detective remarks: “Her diaries completely blow her defence out of the water.”
5. Riding instructor Katrina Walsh appeared to care more about animals than people
In one of the diary entries, read out during the documentary, she wrote: “If it all goes wrong, someone will have to look after my horse.”
6. Police briefly pondered what to charge Walsh with
Interviewed in a more comfortable custody suite, with sofas and a coffee table, Walsh was pressed on her claim that she didn’t want to go along with the murder plot.
“Why didn’t you just walk into a police station?” asked one detective.
Walsh replied: “Whenever I was frightened, I was more frightened of her [Sarah Williams] than anyone else.”
Police later ruled that Walsh played a ‘willing and significant role’ in Sarah’s murder. She shook her head as she was charged - but did not make a formal reply after being charged.
7. A Nokia phone hidden beneath Sarah Williams’ bed was a key milestone - because it tracked down the car
Officers found calls to car dealers in her records, and the last one led them to the seller of a blue Renault Clio.
Sticky tape had been applied to the number plate to turn a ‘3’ into an ‘8’ - but police work saw through it and the car was tracked down to a car lot 55 miles away from the murder scene.
The ‘crucial find’ was key after forensics discovered the car was covered in blood.
8. Sadie Hartley was a much-loved mum and the loss of her family was never far from officers’ minds
An officer in the investigation admits she is missing her family because of long hours and hard work, but remembers that at least she will see them again.
“This lady needs justice, this family needs justice.”
9. The bravery of Sadie’s family
Paying tribute to her mother - and remembering her ‘happy, lovely’ nature - daughter Charlotte says: “She never got angry, all she ever wanted was to talk things through. If this hadn't happened she would still be with us today.
“It was pointless.”
The family attended the trial throughout and were forced to hear harrowing details about Sadie’s death.
Describing the trial, Charlotte said: “I want to be there very single day to make sense of it. I don’t know if it will help myself and my brother, I don’t think anything will.
“I want to know but I don’t think we’ll ever get the answer why.”
On the conviction of the pair, she added: “It doesn’t bring back my mum and 30 years in prison - they are still here. My mum isn’t here any more.”
10. TV crews were there by pure chance.
Filmmakers Raw Cut TV had been making a documentary about Lancashire police at the time when Sadie was murdered and the investigation began - so it was pure chance that they were there.
Lancashire Constabulary allowed the crew to continue documenting the investigation - as well as film the suspects involved - on the proviso that nothing was released until the case had concluded. It has provided a rare and compelling insight into a modern police investigation and the work which officers carry out.