A mother held her hands over her ears as her policeman husband struggled for his life when her lover gassed him to death in his bed, a court heard today.
As their two children slept in another room, she stood by and did nothing to prevent Pc Trevor Buchanan being poisoned by carbon monoxide fumes at their home in Coleraine, Co Derry, it was alleged.
Hazel Stewart's then-lover, dentist Colin Howell, killed the officer just after murdering his own wife by the same method because he wanted to begin a new life with the school playgroup assistant.
He then staged-managed the deaths to make them look like a suicide pact, but 18 years later after his affair with Stewart had ended acrimoniously, and he had remarried, the secret which the two had kept to themselves was revealed in a dramatic confession by Howell to his church elders.
Antrim Crown Court heard how the pair concocted a cover-up which fooled investigating police in the hours after Howell gassed his wife, Lesley, the mother of their four children, before driving across town with her body in the boot to kill Pc Buchanan. It was May 1991.
They were later found in a car in the neighbouring seaside town of Castlerock - Pc Buchanan in the driver's seat and Mrs Howell in the back.
A year later an inquest heard how it was believed they had taken their own lives because they were so depressed and disturbed by the affair.
Before their affair was discovered, Stewart fell pregnant and had an abortion in England. Eventually they split and later remarried, Howell to an American divorcee and Stewart to former police chief superintendent David Stewart.
They shared their secret until Howell finally revealed all in January 2009 and when his ex-lover was detained by police she allegedly said: "What? What? What evidence? What has been said?"
Later she claimed she lied to protect her children and herself because she was frightened, scared and vulnerable. Howell used a garden hose pipe connected to his wife's car and then held it towards them when they were asleep to kill both with the fumes. At one stage Pc Buchanan woke and tried to defend himself.
Last November Howell of Glebe Road, Castlerock, Co Derry admitted his part in the murders and was sentenced to 21 years.
Today, Stewart appeared before a jury of nine men and three women and with her daughter Lisa and son Andrew sitting just feet away, heard how she allegedly played a part in their father's death. The court then heard how she went about hiding the truth by making false statements and lying to police called in to investigate.
Crown prosecutor Ciaran Murphy said: "She stood feet away knowing her husband was struggling for his last breaths, being poisoned by Colin Howell. She showed total and utter callous disregard for her husband and endorsed and encouraged exactly what Colin Howell was doing."
He claimed she was an accomplished liar and added: "She is wholly complicit in the murder of both."