'Demonic savagery' used in 'premeditated, planned assassination'
A jealous ex paralysed her love rival with a stun gun before knifing her to death with "demonic savagery", a murder trial heard.
Sarah Williams, 35, shot "decent, hard-working" communications director Sadie Hartley, 60, in the head with the weapon on the doorstep of her £500,000 home in the village of Helmshore, Lancashire.
She then stabbed and slashed the mother-of-two 40 times in an "orgy of violence" that was the culmination of a 17-month plot, Preston Crown Court heard.
The defendant was said to be obsessed with Ian Johnston, 57, who broke off their relationship after she became "possessive and difficult".
Ski travel firm employee Williams recruited her friend Katrina Walsh, 56, a horse riding instructor, to help with her murderous mission, the jury was told.
Williams planted tracking devices on Mr Johnston's Subaru car to find where he had begun his new life with Ms Hartley - although it also went on to track the defendant's movements when she eventually retrieved them, the court heard.
And a week before the murder she arranged for flowers to be delivered to Ms Hartley in a "sinister" test run - described in court as "almost the stuff of spy novels", jurors heard.
A week later at just after 8pm on January 14 this year, while ex-fireman Mr Johnston was on a skiing trip to Switzerland, Ms Hartley received an unexpected knock at the door.
"What happened next is truly shocking," prosecutor John McDermott QC told the jury.
"Sarah Williams stood on the doorstep. As soon as the door was opened we suggest she lunged at Sadie Hartley with of all things a stun gun - the sort of thing you might use legitimately to prod cattle.
"She pressed it against her - Sadie Hartley's head - and incapacitated her.
"Then with what can only be described as almost demonic savagery, she attacked her with a knife.
"It was a premeditated, planned assassination of an innocent woman."
Mr McDermott said Walsh kept "a remarkable, compelling record" of the "murderous aim" in a diary which was later seized by detectives.
A September 2014 diary entry read: "Sarah came round so got caught up in endless murder plots for Ian's other half", while a June 2015 entry said: "We're also seriously talking of getting rid of her opponent. I agree is probably a good play ... she does seem to be a totally evil bitch."
In December 2015, the co-defendants took a ferry from Hull to Rotterdam and then travelled to Darmstadt in Germany, where they bought the stun gun.
A blue Renault Clio was bought a month later for £430 in cash while Walsh used her Tesco club card to purchase the large kitchen knife used in the killing.
Williams was also caught on CCTV buying size 10 boots, in the hope the large bloody footprints left at the scene would throw police off the scent.
Despite believing they were carrying out the "perfect murder", police were able to track and trace the defendants' movements via the tracking devices, mobile phones and car number plate monitoring, and also caught Williams on camera at the crime scene, it is alleged.
Mr McDermott said walking to the house, knocking on the door, using the stun gun and inflicting 40 knife strokes in such a short space of time showed this was a "no-hesitation, determined and swiftly executed murder" by Williams.
Williams, from Treborth Road, Chester, and Walsh, of Hare Lane, Chester, both deny murder.
The trial, scheduled to last seven weeks, continues on Wednesday.