Sunny von Bülow: Heiress whose husband's trial for her attempted murder was dramatised in the film 'Reversal of Fortune'

The American heiress Martha von Bülow, known as Sunny, spent the last 28 years of her life in a persistent vegetative state, having been found unconscious on 22 December 1980 at her mansion in Newport, Rhode Island. Her second husband, Claus von Bülow, was accused of injecting her with insulin in an attempt to murder her. He was tried and convicted in 1982 and then retried after an appeal.

The case caused a sensation. Its blend of money, murder, high society and a sleeping beauty in a coma held America in thrall. The 1985 retrial, in which von Bülow was acquitted, was the first trial in a US court to be televised. Von Bülow's defence lawyer, Alan Dershowitz, wrote a book about the case, Reversal of Fortune, and it was dramatised in a 1990 film starring Glenn Close and Jeremy Irons (who won the Oscar for Best Actor).

Sunny von Bulow was born Martha Sharp Crawford in 1931, in a railway carriage between White Sulphur Springs, West Virginia, and New York. The wealth came from her father, George Crawford, founder of Columbia Gas & Electric, who was 75 at the time of his daughter's birth. She was an only child and her father died when she was just four, leaving her a fortune valued then – in 1935 – at £75m.

Growing up with her mother in New York, Sunny, as she became known, was taken by Rolls Royce from their Fifth Avenue apartment to the exclusive Chapin School in the city. Summers were spent with her mother and grandmother on the family estate, Tamarlane, in Greenwich, Connecticut. She left school at 18, and had a coming out-out ball at Tamarlane.

It was the life of an archetypal East Coast heiress. She passed university entrance exams but choose not to take up a place. Instead, her mother took her on endless tours of Parisian couture houses and in due course Sunny made it on to Vogue's list of the world's 10 best-dressed women. Her mother, who was a crack shot, also took her to European country-house sporting parties where heiresses and penniless aristocrats could trawl for each other. At one of these, in Austria in 1957, Sunny met and married Prince Alfred von Auersperg, a handsome tennis instructor.

The marriage was to last seven years. It produced two children, Alexander and Annie Laurie. But following the wedding Auersperg continued to be the philanderer he was before, with trophies that included the Italian actress Gina Lollobrigida. After they were divorced, Auersperg managed to lose his million-dollar settlement from Sunny, and his two homes. He settled in Africa, went in for big game hunting, had his possessions confiscated by Emperor Bokassa, was in a nasty car accident and was himself in a persistent vegetative state from 1983 until he died in 1990.

In 1964, when her children were aged six and five, Sunny met a debonair bachelor at a London dinner party. He was Claus von Bülow, a barrister who had graduated from Cambridge at 19, and had been in the Danish winter sports team in 1948. After some years in Lord Hailsham's chambers he had become J. Paul Getty's right-hand man. Claus and Sunny fell in love.

Sunny divorced Alfie and married Claus in 1966. They celebrated with a ball with 230 guests at Claus's flat in Belgrave Square, decorated like an 18th-century Indian palace. They had a daughter, Cosima, in 1967 and settled in the US living in Fifth Avenue, New York, and spending the summer months at their Rhode Island villa, built in 1904 as a replica of Hedworth House in Co Durham. It was used as the location for the film High Society.

A 1985 article in Vanity Fair described their life together. Typically Sunny rose around 11, phone her mother for an hour, was chauffeured to her exercise class, did a little shopping, had lunch, changed into her pyjamas, and watched television with Claus. Occasionally she appeared at parties, fabulously gowned. She went to bed early, sharing a bed with Claus and their four Labradors.

Some of her friends later said that she had a drug and alcohol problem. Professor Vincent Marks of Surrey University, a diabetes specialist who was an expert witness at von Bülow's second trial, testified that her medical records supported these claims. But others, including her two older children, denied this.

A number of incidents pre-figured her final coma in 1980. In December 1979, 12 months earlier, Sunny had been taken to hospital unconscious. Claus had rung their general practitioner, who came to the house just in time to save her life with external heart massage and mouth-to-mouth resuscitation and got her to hospital. She had inhaled vomit, which caused oxygen deficiency and low blood sugar. Her medical notes record that she was strongly advised "to abstain from alcohol, barbiturates and tranquillisers in any shape or form."

The following April Sunny twice went into the Presbyterian Hospital in New York for belated investigations. Her medical notes record recent drowsiness, unsteadiness and slurred speech; a week before admission her balance had been poor. She admitted to having drunk heavily, and taking barbiturates and tranquillisers, traces of which were found in her urine. She went home without a diagnosis and remained well for six months. On 2 December 1980 she was admitted to hospital, having taken 75-100 aspirins. That morning, Claus's mistress had delivered Sunny evidence of their affair.

Three weeks later, on 21 December 1980, Sunny von Bülow was admitted to hospital with a profound coma from which she never recovered. That morning, her husband had returned from walking the dogs to find her unconscious on her bathroom floor. Her blood sugar was very low, she was cold, and she had a torn lip. Medical investigations showed high levels of alcohol, barbiturates, and beta-blockers she had been prescribed for migraine. She stopped breathing in hospital but was resuscitated. She was transferred to Columbia-Presbyterian Hospital in New York in 1981, and later to a Manhattan nursing home. She was kept alive with excellent medical and nursing care; in 2000 this cost $1.2m of her $6m a year income.

The events of that morning were to be picked over in forensic detail thereafter. The police were invited to search the Bulows's apartment and found a vial of insulin and a syringe. The syringe tested positive for insulin and the hypothesis that Claus von Bülow had injected his wife in order to bring about her death was formed. The marriage was under stress because Claus wanted to work while Sunny wanted him by her side. He was having an affair. He stood to gain far more as her widower than if he divorced her. And, most telling of all was the medical test – her blood sugar was low and her insulin level was high.

A prosecution, funded by Sunny's two children by her first marriage, was brought. Claus was charged with two counts of attempted murder – the first relating to the December 1979 episode. The trial focused heavily on the syringe, and the evidence of Sunny's maid, Maria Schrallhammer, who testified to having seen insulin in Claus's sponge bag eight months before her mistress's final coma. Claus was found guilty but, with the financial backing of Sir Paul Getty, appealed the conviction successfully on the basis that evidence for the defence had been withheld. A retrial was ordered.

In the 1985 trial Claus's lawyer, Alan Dershowitz, successfully challenged the medical evidence that the coma was insulin-induced, bringing to bear nine medical experts specialising in insulin and hypoglycaemia. The court found there was no case to answer. Dershowitz later wrote about the case in a book Reversal of Fortune, whose forensic detail was somewhat emasculated by the film of the same name.

Sunny von Bülow was a charming, beautiful, intelligent, shy and unhappy woman who drank heavily and popped pills by the handful. Four days before Christmas 1980, she went to bed having drunk heavily and taken quantities of prescription medicines. The following morning she either slipped on her bathroom floor or passed out, knocking her head. She was not found immediately. She was taken to hospital and never regained consciousness. She survived for 28 years in a persistent vegetative state, believed to be the longest case ever recorded.

Caroline Richmond

Martha "Sunny" Sharp Crawford, heiress: born 1 September 1931; married 1957 Alfred von Auersperg (died 1990; one son, one daughter; marriage dissolved 1965), 1966 Claus von Bülow (one daughter); died New York 6 December 2008.