Successful businesswoman Sadie Hartley was adored by her family, partner, friends and anyone who knew her.

Described by her daughter as her “hero”, Sadie was brutally stabbed to death in her own home by a bitter and twisted love rival.

Sarah Williams had been planning Sadie’s slaughter for 18 months and carried out the cold-blooded killing with chilling precision.

Furious Sadie was in a relationship with the man she had an affair with, Ian Johnston, Williams hatched her murderous plot and used her friend, Katrina Walsh, to help her carry out the bloody scheme.

She thought she had committed the perfect murder with no detail overlooked – but a painstaking police investigation into Sadie’s death uncovered the one fatal flaw.

Lucy McHugh threatened to tell mum she was pregnant day before she was ‘murdered’

Williams was convincted of the mum-of-two’s murder and is now spending 30 years behind bars.

Walsh was also jailed for murder and must serve 25 years for the “evil killing”.

Sadie had just returned home from riding her horse when she was attacked in her own home in Lancashire on January 14, 2016.

She was in the house alone as her partner was away skiing.

When there was a knock on the door at 8pm that evening Sadie thought nothing about answering – totally unaware of what would happen next.

Sarah Williams had plotted the murder for 18 months
Her friend Katrina Walsh was also jailed for 25 years

The 60-year-old as first stunned with a cattle prod by Williams who then stabbed her 41 times in what has been described as an “orgy of violence”.

The 35-year-old believed, that with Sadie out of the way, she would be able to win back her former lover Ian.

He had ended their relationship after she became “difficult and possessive” and moved on to a new life with Sadie.

Ian thought he would never have to deal with Williams again but she began to plot how she could clear the woman she viewed as her love rival out of the picture.

Over the next 18 months she devised what she thought was the perfect crime.

Sadie was first stunned with a cattle prod and then stabbed 41 times ,’

Williams, who even described herself as a “she devil” and a “little psycho” couldn’t resist sending Sadie a poison pen letter.She claimed she and Ian had had “unbelievably fantastic sex” behind her back, hoping it would end their relationship.

It didn’t, so Williams began to put her plan into action.

First, she and Walsh travelled to Germany to buy the stun gun they used to paralyse Sadie.

The pair also bought boots several sizes too big so they could cover their tracks.

The pair also bought boots several sizes too big to cover their tracks 
The pair also bought a stun gun in Germany

Next they placed a tracker on Ian’s car so they could keep a track of his movements and find out where the couple were living.

Williams and Walsh also scoped out the area so there was no element of surprise, buying a second hand car with false number plates so they wouldn’t be detected.

Their final sinister move was deliver flowers to Sadie a week before the gruesome murder so Williams could identify the woman she was to kill.

On the night of the attack, the murder was carried out with such savagery is shocked even the most hardened police officer.

Sentencing Williams and Walsh, Mr Justice Turner said Sadie had been “slaughtered like an animal”.

They delivered flowers to sadie so that Williams could identify her victim

He added: “Doubtless, the features of secret agent-style intrigue carried with them elements of fantasy but this was no harmless world of make-believe,” he said.

“It was a game of death.

“Let no one believe this was a crime of passion. This was a crime of obsession, arrogance, barbarity and pure evil.”

After the killing, the pair knew they still had work to do.

Walsh helped to hide the evidence, including the knife used to stab Sadie and the stun gun, at a nearby farm.

Walsh hid the evidence at a nearby farm

Police found Sadie’s mutilated body the following day when one of her concerned employees reported her missing.

Straight away, officers suspected Williams and she was arrested at her home in Chester on January 17 – three days after she had killed Sadie.

Walsh was arrested a day later.

But there was still a mountain to climb when it came to proving the pair were guilty.

Detectives had hoped to find a wealth of forensic evidence inside Williams’ home but instead found it had been scrubbed “top to bottom” with bleach.

Ian Johnston had broken off his relationship with Williams and started a new life with Sadie

Initially Williams remained “cool, calm and collected” as she was grilled by officers but when she was told her mobile phone hd placed her near the scene of the murder she went “into her shell” and would only answer with “no comment”.

Walsh claimed she had memory difficulties.

But it was the discovery of her diaries that proved the breakthough officers needed.

Contained in the pages was the first mention of the plot to kill Sadie.

It destroyed her claims she suffered from short-term memory loss and the pair’s crime was exposed.

Despite the lengthy prison sentences handed down to Sadie’s killers, for her family it can never make up for the huge hole in their lives.

Her daughter, Charlotte, said: “My mum was a very fun loving person. She didn’t judge anyone. She literally didn’t have anything bad to say about anybody.

“She was my hero in some respects. There’s nothing I could fault with her whatsoever. She was looking to retire.

“She was really looking forward to me and Robert having children, and spending a lot more time with us.“I just want her to be remembered for the happy lovely lady she was; this wasn’t supposed to happen to her.

“The fact that someone has taken her life for no reason whatsoever is disgusting.

“She’s got two children; she’s got her whole family that loves her. It’s just numbing. I feel strongly that it ruined me and my brother’s life.”