Michael Coulton, 53, who regularly invited prostitutes to the marital home while his wife was at work, stabbed Patricia to death, a jury at Reading Crown Court was told.
Mrs Coulton's body was found in the passenger seat of her car in a remote corner of the grounds of Lynwood nursing home in Sunningdale, Berkshire, where she worked, in January 1997. Mr Coulton denies the killing.
Richard Latham QC, for the prosecution, said Mr Coulton, an officer with the diplomatic protection squad assigned to the Palace at the time of his wife's murder, was able to remain one step ahead of the police investigation because he was a serving police officer.
The court heard that Mrs Coulton, 52, was killed after she had driven away at the end of her shift. She had left her car beside the entrance to the home and carried both a mobile phone and a rape alarm in the vehicle. Her body was found the following morning and Mr Latham said there was no sign of sexual assault nor any evidence that her bag had been rifled through. There was no damage to the car and the killer must have been waiting inside when she came out of work or persuaded her to let him in, he said. Mr Coulton had the key to the car and his presence outside her work would not have been "unduly significant or threatening" to her.
"We suggest she was taken by surprise at the moment of the fatal attack and we suggest right up to that moment she felt secure because we say she was with her husband," Mr Latham said. When his wife did not return home, Mr Coulton went through the motions of tracking her down but failed to try to contact her on her mobile phone. "If he knew she was dead... there was no point."
The couple, described as having an "unusual relationship" remarried in September 1995. On the night of the killing, various people at Lynwood heard screams but they believed it was the sound of foxes.
The trial continues today.Reuse content