A wealthy antiques dealer who strangled his seven-year-old daughter has admitted murder halfway through his trial.
Robert Peters, 56, strangled Sophia with a dressing gown cord while alone with her at his £1 million family home in Wimbledon last November.
Afterwards, he called 999 to report what he had done and the child was rushed to hospital, but died the following day.
The killing came just over a month after Peters was found not to be a risk by a child protection team.
Peters had admitted manslaughter but denied murder, claiming he was hearing voices at the time.
But three days into his Old Bailey trial, he dramatically changed his plea, watched by Sophia's mother Krittiya - his third wife - and other family members.
Peters had recently ended a two-and-a-half-year affair with a married Home Office official he met online.
Mrs Peters had caught him on the phone with the woman but forgave him and he moved back home, the court heard.
He was also worrying about his finances and claimed his Kensington-based oriental antiques business was going bankrupt, even though he had a Jaguar car and plenty of money in the bank.
In the months before the killing, Peters searched the internet for "serial killers", "treatment of child killers in prison" and "premeditated murder".
He chose his opportunity to kill her before she was due to return to her £5,000-a-term boarding school after the half-term break.
Peters waited until his wife had gone out before he woke Sophia up in bed by tying a cord around her neck and strangling her for up to half an hour.
She asked him what he was doing and Peters said "sorry", but carried on as she struggled, the court heard.
When officers arrived at his Blenheim Road home, Peters calmly told them: "She's upstairs. I've strangled her."
She had a weak pulse and was rushed to hospital, joined soon after by her mother, who was escorted there by police.
Sophia was treated in intensive care but died from brain damage the next day, on November 4 last year.
Following his arrest, Peters admitted not being a good father and said he had been suffering a breakdown.
He said he had been thinking of killing his wife and family for several weeks so they could be "spared the pain and upset when he became bankrupt".
Peters told police he had been visited by a child protection team and feared Sophia would be taken into care.
But an assessment had already concluded on September 27 that he was not a risk to himself or others and the case was closed.
It can now be reported that Peters' second wife Francine claimed he had throttled her during their marriage, which ended acrimoniously in 2009.
She said in a statement in the wake of the killing: "He grabbed me around the neck, was strangling me. It was on a hot summer month. I had marks on my neck."
She also alleged he was controlling and had headbutted her and slapped her around the face.
But Jim Sturman QC, defending, dismissed her account, which was not put before the jury, saying it "never happened".
Mr Justice Edis remanded Peters into custody to be sentenced on Monday.