Sally Clark, 35, was convicted, by a majority verdict of 10 to two at Chester Crown Court, of killing the boys. The jury took eight hours to decide that she had smothered 11-week-old Christopher on 13 December 1996, and shook or smothered to death eight-week-old Harry on 26 January 1998. Her third child, a one-year-old boy, is in care.
Mr Justice Harrison said there were other matters to investigate before he passed sentence and she would remain in custody until then.
Clark had denied the murders, claiming that she found both children limp and lifeless. She had said she loved the boys "more than anything in their own little ways, more even than my husband". The court had been told by expert witnesses that the chances of the children both suffering cot deaths were one in 73 million.
Robin Spencer, for the prosecution, told the jury during the 18-day trial that the babies died "at their mother's hand" on both occasions in the upstairs bedroom of their cottage in Wilmslow, Cheshire.
Clark, who was suffering from alcoholism and depression, had reached the end of her tether, he told the court. She had moved from London and was working as a junior solicitor at Addleshaw Booth solicitors in Manchester, where her husband, Stephen, was a partner. On the day Harry wasfound dead, his mother had twice visited the same off- licence: first to buy three bottles of wine, and later a further four or five bottles. Clark, who usually drank alone, said the wine was for a dinner party.
She told the jury she had not yearned for children when Christopher was conceived. "I was only three years qualified ... but my biological clock was ticking," she said. A christening was planned for him.
On the nights of both babies' deaths, Mr Clark, 33, originally from Sheffield, was either away from home or about to leave. He was at the office Christmas party when his wife said she found Christopher looking "dusty grey" in his cot. Within minutes, she was trying to let an ambulance crew in but could not find the key to the side door.
Christopher's post-mortem examination found bruising to his legs, a cut and bruising on his lips and gums consistent with smothering. But a minor infection was found in his respiratory tract, so the murder was put down to cot death.
Harry's conception, within three months of the first child's death, was part of the "healing process", said Clark. But he was born three weeks premature, slept less than Christopher and cried more. He was, his mother admitted, "a little devil". He was found slumped in his bouncer seat. A post-mortem examination uncovered evidence that he had been shaken to death - damage to the spinal cord, eyes, a fractured rib and possible tearing to the brain.
Re-examination of Christopher's lung tissue, which had been retained after his death, then uncovered evidence of bleeding into the lungs several days before death, consistent with attempts to smother.
Detective Inspector John Gardner of Cheshire police, who led the investigation,rejected suggestions that police should have taken more action after Christopher's death. "We were dealing with the hardest thing we have to do as police officers - going to a parent and ... accusing them of killing their own child."
When the verdict was announced yesterday, Mr Clark held out his arms toward the jury in a gesture of disbelief. He mouthed "I love you", at his wife and later, in a statement, said she was a "caring mother" and her sons were "not murdered".
Mr Clark, claiming medical evidence was flawed, said: "I would ask any parent who has suffered the agony of cot deaths to come forward and help put right this terrible wrong and prevent others having to tread this awful path."Reuse content