Mr Simpson, once one of the best-loved sportsmen in the US, listened as he was described as a man who became so fixated by his young blonde wife that he even dictated what kind of clothes she wore, how she wore her hair, and how much money she had to spend.
"He killed her for a reason almost as old as mankind itself. He killed her out of jealousy. He killed her because he couldn't have her, and he didn't want anyone else to have her," Christopher Darden, prosecuting, told a hushed, packed Los Angeles courtroom in his opening statement. The trial swung into action, watched by tens of millions of television viewers, with a prosecution effort to destroy Mr Simpson's public image as one of the best running backs in the history of American football, who l ater became a popular actor in the Naked Gun films and a star of Hertz commercials. The jury should see "the private face" of the star, said Mr Darden, "the face that Nicole Brown encountered during the last moments of her adult life".
The 38-year-old black prosecutor reeled off incident after incident in an effort to prove that Simpson murdered his ex-wife, Nicole Brown Simpson, 35, and Ronald Goldman, a 25-year-old waiter. Their mutilated bodies were found outside her townhouse in Brentwood, Los Angeles, on 12 June.
Relatives of the victims and of Simpson listened from the public seats as Mr Darden described how Nicole Brown was an 18-year-old waitress when she met Simpson. He was a millionaire with a mansion, one of the most recognisable people in the country; she was a mere girl, who shared an apartment. He bought her gifts, found her a new home, even brought her a Porsche as he established "complete financial control" over her life.
But as their relationship developed so, too, did his regime of "force, violence, fear and intimidation", Mr Darden said. He would undermine her self-esteem, calling her a "fat pig" when she was pregnant. Heattempted to isolate her from her friends, male and female.
Mr Darden cited an incident in 1989, when Nicole Simpson was beaten up by her husband, who later pleaded no contest to a spousal-abuse charge. He quoted an occasion - after their marriage broke up - when Simpson accosted his ex-wife when she was at a restaurant with a male friend, staring at them for minutes on end. And he described the allegation that Simpson began stalking her.
Beyond the issues, almost as important to the outcome of the trial is the image which both sides create of Simpson. Is he the ex-footballer who still looks like a man in peak condition, who made a fitness video weeks before the murders? The prosecution are likely to argue that such a man was more than capable of knifing to death two people. Or is he a middle-aged man, crippled by years in one of the toughest professional sports in the world? A tired old golfer who could never muster the strength to tackle a 25-year-old fitness buff like Ronald Goldman? Yesterday Judge Lance Ito agreed to allow Simpson to approach the jury and show his injuries during his lawyer's opening statement. Whether this works remains to be seen. If there's o ne image of O J Simpson branded into every American mind it is that of a Hertz television commercial: an all-too-healthy O J is seen running through an airport, displaying no signs of his sporting wounds.