A jealous wife who murdered her husband by bludgeoning him to death with a hammer has been sentenced to life in prison.

Office manager Sally Challen, 57, of Ashton Place, Claygate, admitted to intentionally killing Richard Challen, 61, at their marital home in Ruxley Ridge, Claygate, on the afternoon of August 14, last year.

However she denied murder, claiming she was mentally ill when she hit her husband 25 times with the hammer.

The jury unanimously found her guilty of murder, agreeing with the prosecution’s case that Mrs Challen had made a “conscious and calculated decision” to kill her husband after discovering he had that day been in contact with another woman he had met on the internet.

The court heard the couple, who had been married for 31 years, separated in November 2009 but were planning a trip to Australia in an attempt at a reconciliation.

On the morning Mr Challen was murdered, the pair were busy clearing their marital house in preparation for the trip.

Mrs Challen decided to take a hammer from her own house in Ashton Place to kill her husband if, in the words of prosecutor Caroline Carberry, “things didn’t go her way”.

Mrs Challen made a trip to the Co-operative supermarket in Claygate to buy ingredients to cook for her husband’s lunch.

On her return she discovered the house phone was in a different place, making her suspicious Mr Challen had called someone. She dialled 1471 and discovered a call had been made to a woman called Susan Wilce, who Mr Challen had met on an internet site called Dinner Dates.

The jury was told Mrs Challen then asked her husband whether they could see each other the next day, knowing from spying on him that he had planned to make a trip to the south coast that day to meet Susan Wilce.

When Mr Challen refused to reply, Mrs Challen made her husband some food and, as he ate, pulled the hammer from her handbag, hit him over the head from behind and then continued to hit him while he lay on the floor.

A forensic doctor told the court the wounds to Mr Challen showed the attack had been “severe” and when police discovered the body the following day there was a large quantity of blood on the floor.

The court was also told Mrs Challen stuffed cloth into Mr Challen’s mouth until he stopped breathing.

After killing her husband, Mrs Challen covered the body with some old curtains from the loft and went upstairs to change her clothes.

She then took some paper from the printer and wrote a note, which she left on Mr Challen’s body, which said: “I love you, Sally”, before washing the dishes and driving home.

She returned to Ruxley Ridge later to look through Mr Challen’s briefcase, check his computer and listen to messages on his phone.

The following day, Mrs Challen drove her son David to work at Carluccio’s in Kingston and then drove to Beachy Head in East Sussex.

From there, she called her cousin, saying she had killed her husband and was at the notorious suicide spot.

Meanwhile Ross Hardy, a chaplain from the suicide prevention team at Beachy Head, spotted Mrs Challen near the cliff’s edge just after noon, after being alerted by police that her car had been found in the area.

Detective Sergeant Mark Rosser, who took over from Mr Hardy, persuaded Mrs Challen to hand herself over to police.

During the negotiations to get her away from the cliff, Mrs Challen told both men she had killed her husband. Officers from Surrey Police found the body at Ruxley Ridge, the jury was told.

Sentencing Challen, Judge Christopher Critchlow told her she would serve a minimum of 22 years in jail.

Mr and Mrs Challen’s son James and David Challen said in a statement following the verdict: “We would like to thank our family and friends for their continuing support during what has been an incredibly difficult time.

Detective Chief Inspector Chris Raymer, of Surrey Police’s major crime investigation team, said: “The facts of this case were put before the jury and they have decided Mrs Challen is guilty of murder. This has been an extremely difficult time for the family and friends of this couple, in particular their two sons, and our thoughts remain with them.”

Challen's defence failed to convince jury

Sally Challen admitted from the moment she was arrested she had intended to kill her husband when she attacked him with a hammer at their marital home in Ruxley Ridge in Claygate.

During the trial, Challen’s defence tried to convince the jury their client had killed her ex-car salesman husband while suffering from depression and was therefore not guilty of murder.

They heard from a psychiatrist Dr Timothy Exworthy, who had interviewed Challen on three occasions following her arrest in August last year, who said in his opinion she was suffering from “a depressive condition of moderate severity”.

The court heard Challen had started taking antidepressants during her marriage with Mr Challen, after suspecting him of having affairs and sleeping with prostitutes.

By the time she murdered her husband they had been separated for more than six months and were living in separate houses.

But Mrs Challen, an office manager at the Police Federation in Leatherhead, had started to spy on Mr Challen, using her lunch breaks to enter his house when he was not in and getting a neighbour to report whether he had gone out in the evening.

She would even go to the house in Ruxley Ridge in the night, when Mr Challen was asleep, and look at messages on his mobile phone that she knew he kept in a shoe next to his bed.

While in custody, she admitted to Dr Exworthy that on one night she entered the house with a hammer intending to hit him, but on that occasion she had not gone through with it.

Although a lot of Challen’s behaviour appeared bizarre – she changed her trousers after killing her husband because she was afraid they looked silly – the prosecution painted a different picture from a woman suffering from a mental illness.

Instead, barrister Caroline Carberry said Challen had made a “conscious and calculated decision” to kill her husband because she was “consumed by jealousy”.

The jury heard from another psychiatrist, Dr Paul Gilluley, who had also interviewed Challen on several occasions after her arrest. He said there was nothing psychologically wrong with her and she had killed Mr Challen in a fit of anger.

Mrs Carberry told the jury: “This was planned. This was thought through. She was consumed by jealousy, suspicion and anger and made a conscious decision to kill her husband in the most brutal way.”