The actions of a murder victim have helped to convict her killer by managing to scratch her attacker's face before she died in a ferocious attack at her home earlier this year.

Sara McKenzie, 62, went to Joy Boulton’s home in Church View, Ash, in a jealous rage on the morning of May 11, 2023, and when Joy opened her front door, she was bludgeoned to death with a heavy implement.

Joy's body was found by her fiancé when he returned from work that evening. 

DNA found under Joy’s fingernails came from the defendant and blood was also found on the defendant’s clothing, which matched Joy’s DNA.

Guildford Crown Court heard how McKenzie had previously been in a long-term relationship with Joy’s fiancé, Trevor Dibnah.

McKenzie had made efforts to rekindle their relationship and accused Trevor of breaking her heart, but he told her that he was not going to leave Joy.

After Trevor and Joy moved in together in October 2022, McKenzie went to their home to confront Joy. Joy also believed abusive phone calls she had received had come from the defendant.

After Joy shared news of her engagement on social media in December 2022, there was a fire in the shed at the rear of McKenzie’s property, where her ex-partner’s belongings were being stored. 

And her jealously boiled over on May 11, 2023, when McKenzie went to Joy’s house with the sole intention of killing her, striking her multiple times in a sustained and ferocious attack with a heavy object which left her with catastrophic head injuries which were to prove fatal.

Joy’s final act was to scratch McKenzie’s face, which proved critical in proving McKenzie was responsible after her DNA was discovered under Joy’s fingernails.

McKenzie, a fan of murder mysteries, realised that the police had a record of her DNA and constructed an elaborate cover-up to explain why her DNA would be found under Joy’s fingernails.

She claimed she had been the victim of a robbery earlier that day, during which the female suspect had scratched her and grabbed a handful of her hair.

McKenzie told police that she thought the woman had been after her DNA and tried to suggest that the same woman had also attacked Joy. 

Despite house-to-house enquiries in the area, no evidence of a robbery was found.   

McKenzie also tried to conceal her crime by disposing of the clothing she had worn and the weapon used. She had a bath to remove any trace of blood and cleaned it up afterwards.

But forensic scientists were able to locate traces of Joy’s blood in McKenzie’s bath using luminol, a substance that can identify a trace of blood that has been diluted 10,000 times.

McKenzie showed no remorse, went to work as normal and even visitied the petrol station to fill up her car. She was later captured on police body-worn footage at the scene of the murder chatting with no apparent concern for Joy.

After a five-week trial at Guildford Crown Court, on Thursday (November 30) a jjury reached a unanimous verdict in finding McKenzie, of Fairview Road, Ash, guilty of murder.

McKenzie was also found guilty of perverting the course of justice in relation to the claims she had made about being the victim of a robbery.

Detective Chief Inspector Kimball Edey from the Surrey and Sussex Police Major Crime Team, who investigated the case, said: “Firstly, I would like to offer my condolences to the family and friends of Joy Boulton whose loss cannot be underestimated. They have been left devastated by Joy’s death.

“McKenzie’s motive for killing Joy was simple – she wanted what Joy had. McKenzie has a previous history of jealous behaviour including, although it was never proved, burning down a shed containing Trevor’s belongings after finding out he had got engaged to Joy.

“McKenzie went to Joy’s that morning with the sole intention of killing her so that she could get Trevor back. The rage and brutality McKenzie used when she attacked Joy cannot be overstated –sadly, Joy never stood a chance.”

DCI Edey added: “I would like to thank my team who worked tirelessly on this investigation to ensure that McKenzie was found guilty today. This level of violence simply cannot be condoned in our local communities and we will always do everything we can to ensure those responsible are brought to justice.”

Paying tribute to Joy, her family said: “We are deeply devastated by this senseless act of violence which has changed our lives forever.

“Joy was a very caring person, who was always ready to help other people whenever she could despite having many health and mobility problems herself. She fought many health problems over the years but always battled on."

They added: “She will be forever missed and always loved. May she rest in peace.”

Rebecca Millardship from CPS South East said: “This was a ferocious and focused attack, which continued even once the victim was lying on the floor.

“Joy was able to scratch her attacker’s face just before she was incapacitated, giving us vital DNA evidence from under her fingernails that helped to secure the conviction.

“We were also able to demonstrate to the jury that there was a pattern of behaviour leading up to the murder, with Joy confiding in friends about the abuse she had suffered previously from the defendant.

“Despite the weight of evidence against her, the defendant continued with her false claims that she had been robbed on that day, as a way of trying to account for the injuries that Joy had inflicted on her in self-defence. We were able to prove to the court that this was not possible. 

“We hope that this verdict brings some small comfort to Joy’s family.”

Sara McKenzie will be sentenced at Guildford Crown Court on Monday (December 4).