Nancy Pexton and Jennifer Abbott

IN the end, the best explanation the Old Bailey heard was sibling rivalry – a one-sided jealousy, at least, and a relationship drenched in bubbling resentment.

But as Nancy Pexton, 70, said nothing during her trial for murdering her sister in Camden Town last June, the question where the anger first took root was unanswered.

The court heard that Jennifer Abbott, 69 – just nine months her junior – had been stabbed several times at her home in Mornington Place last June.

The dead woman’s son, Brad Carlson, said in a statement read to a sentencing hearing on Friday: “Without her in my life it feels like the star in my solar system is gone. Losing a mother is painful enough but the circumstances in which she died feel like a night­mare which I cannot wake from.”

The circumstances had shocked everybody living on the estate in the backstreets of Camden Town. Ms Pexton had left her sister’s body with tape covering her mouth, while Ms Abbott’s pet corgi, Prince, was locked away in another room.

Ms Pexton had sent angry messages to Ms Abbott and on a list of reminder notes on her phone, she had written: “I am planning to kill my sister whom I love but she destroyed my life with her mouth. Loose lips can sink ships and she sunk my ship. ”

Mr Carlson had told an earlier hearing of the tempestuous relationship between the two sisters, although it was not said what had fuelled the final breakdown. “There was chemistry between them, love at times and at times anger, and resentment,” said Mr Carlson. “Sometimes they made up, sometimes they went long periods without talking.” A prosecutor suggested it came down to envy, telling the court: “For all sorts of reasons she [Ms Abbott] had what Pexton did not.”

Jennifer Abbott

Judge Anuja Dhir KC handed down a life sentence, with a minimum tariff of 22 years. Ms Pexton will be in her early 90s before she is eligible to appeal for her release. Judge Dhir said the taping of her sister’s mouth was a “deliberate act of degradation”, adding: “It was callous, demeaning and cruel, this action taken alone demon­strates the depth of your animosity and hostility towards your sister on the day of the killing.”

She told Ms Pexton, who was appearing via videolink from HMP Bronzefield: “Also before leaving the flat you took your sister’s most prized possession, the Rolex watch given to her by her only child Brad in gratitude for the sacrifices made by her.” The watch had been a key clue when detectives realised the treasured timepiece – which Ms Abbott rarely appeared without – was missing.

She was discovered when a neighbour used a scaffolding pole to break down the door after he became concerned he could not hear her dog barking.

The last time Ms Abbott, who sometimes went by the name Sarah Steinberg, was seen alive was on a doorbell camera when she took her dog Prince for an early morning walk. Ms Pexton later spoke to her on the phone and travelled by bus to the flat. She left after an hour and called her GP to say she had taken an over­dose. She was arrested a few days later in a bed at UCLH. Police decided to release footage of the moment she was arrested on a hospital ward last week. During questioning, Ms Pexton was asked why the diamond encrusted watch had been found in her bag.

She replied: “Oh yes that’s my sister’s. She asked me to look after it”. Mr Carlson had told the court earlier that he had given it to her as a gift in 2004 to thank her for everything she had done for him.

And in his statement for the hearing, he added: “She was a single mother raising her only child, committed to providing me with the life she was not lucky enough to have – boarding school, quality education. Most importantly she gave me love and a feeling of belonging and pride. She was my whole world, she was everything to me.

“What happened to her in the place she should have been safest in her home, is something I struggle to come to terms with.” DI Barry Hart said: “While no sentence can undo the devastation caused to Jennifer’s family and friends, this sentence demonstrates that those who commit the most serious offences will be relentlessly pursued and brought to justice.”