This dramatic footage reveals the moment police investigating the ‘demonic’ murder of Sadie Hartley finally catch up with jealous killer Sarah Williams.
Five police officers burst into her bedroom at 3.10am to tell the shocked ski instructor she is under arrest.
Looking bedraggled and confused, she sits bolt upright in her bed as PC Jane Davies reads Williams her rights.
The scene is a stark contrast to the picture of a cold and calculated killer painted in her murder trial.
‘Jealous and obsessive’ Williams exacted terrible revenge on Ms Hartley who she saw as her love rival. She had met Ms Hartley’s partner Ian Johnston on the slopes of the Chill Factore near the Trafford Centre and they began an affair. Mr Johnston told the court he had tried to end the relationship but Williams wanted him for herself.
The 35-year-old had recruited her friend Katrina ‘Kit’ Walsh, 56, and the twisted pair spent 17 months plotting to kill Ms Hartley, 60, a mum-of-two and a successful businesswoman.
On the evening of January 14 this year - Williams knocked on the door of the home Ms Hartley, 60, shared with former fireman Mr Johnston on Sunny Bank Road in Helmshore, Rossendale.
When Ms Hartley opened the door Williams lunged at her with a 500,000-volt stun gun then knifed her 40 times.
Williams simply walked away as her target was dying on the doorstep, later meeting up with Walsh to get rid of the evidence.
Ms Hartley was found a day later face down in a pool of blood in the hallway of her £500,000 home.
Unaware the net was closing in, Williams and Walsh settled down to watched the hit Abba tribute film Mamma Mia.
Just three days after the killing, police paid Williams a visit at her home on Treborth Road in Blacon on the outskirts of Chester.
A TV production company, Raw Cut TV, which had been filming a documentary about Lancashire Police for ITV, captured the dramatic moment officers burst into her bedroom and carried out the arrest.
The programme, The Murder of Sadie Hartley, will be broadcast at 9pm on September 1.
Following the conclusion of their trial at Preston Crown Court last week, Williams was given a life sentence and ordered to serve a minimum 30 years behind bars.
Walsh, also from Chester and who kept a diary about the murder plot, was told she would serve at least 25 years as part of her life sentence.
