17/08/2016 15:01 BST

Sarah Williams Jailed For Life For Murdering Love Rival With Stun Gun And Knife

She used a kitchen knife to stab her victim with 'demonic savagery'

A jealous ex-girlfriend has been jailed for life for the gruesome stun gun murder of her love rival.

Sarah Williams, 35, shot successful businesswoman Sadie Hartley, 60, with a 500,000-volt stun gun as her unsuspecting victim answered the door at her home, Preston Crown Court heard.

Seconds later, with “demonic savagery”, she used a kitchen knife to stab the semi-paralysed mother-of-two in the face and neck, inflicting more than 50 injuries, before leaving her in a pool of blood in the hallway of the £500,000 house in Helmshore, Lancashire.

Family handout/PA Wire
Sadie Hartley with her partner Ian Johnson in Venice in 2015 

Hartley was home alone because her partner, Ian Johnston, was away on a skiing trip in the Swiss Alps.

Williams, described as a “bunny boiler” and “kept woman” who was already in a relationship with a wealthy 75-year-old “sugar daddy” and having affairs with other men, had a brief fling with ex-fireman Johnston.

He had dumped “obsessive and jealous” Williams and begun a new life with Hartley - but explicit photos and sex texts continued between the pair while Williams plotted the “perfect murder” for 18 months to kill her rival and win him back.

Lancashire Constabulary/PA Wire
The knife used by Sarah Williams to murder Sadie Hartley 

On Wednesday she was convicted of the murder on January 14, alongside her accomplice, horse riding instructor, Katrina “Kitt” Walsh, 56, following a seven-week trial.

Both women, from Chester, had denied murder and blamed each other. Williams was sentenced to life in prison with a minimum of 30 years, while Walsh received a minimum of 25 years.