Next to me in the front row of the courtroom sat gadfly writer Dominick Dunne, who came to the trial believing the football hero was guilty of killing his ex-wife, Nicole Brown Simpson, and her friend Ronald Goldman. But in that moment the playing field had changed.
"Did you see that?" Dunne whispered to me. "He took those gloves and he ran with them as if he was running down a football field. This case is over."
As if encased in amber, that moment from Simpson's "Trial of the Century" lives on in my memory.
Stunned by the scene, I called prosecutor Chris Darden on the phone at the day's end, asking why he had Simpson try on the gloves.
"What did it look like to you?" he asked me.
"It looked like they didn't fit," I said.
"Well," Darden said, "I looked at his hands and I looked at the gloves and I thought they would fit."
Darden had violated a cardinal rule of courtroom law: Don't demonstrate something in front of a jury unless you know the outcome.
That day, Simpson's charismatic lawyer, Johnnie Cochran, coined a phrase that would become an enduring motto in pop culture: "If it doesn't fit, you must acquit."
There would be months more testimony, but that was a turning point. It was June 15, 1995, a year and two days after the slashed bodies of Nicole Simpson and Goldman had been found outside her home.
Police said they found a bloody glove at the scene and many hours later a lone police detective, Mark Fuhrman, scaled a wall outside O.J. Simpson's house and said he found a match. Now, the gloves appeared not to fit the suspect and the credibility of Fuhrman would be irrevocably damaged when tapes revealed him making disparaging remarks about blacks.
Were the gloves planted? Was it a setup? Those questions would haunt the case forever.
No knife was located and there were no bloody clothes at Simpson's home. DNA evidence was compromised by shoddy police work.
Lead prosecutor Marcia Clark, who was watching her case fall apart, came to my courthouse office one morning and asked, "Do you think we even have a chance?"
In the intervening year, the Heisman Trophy winner, sportscaster, movie star and commercial pitchman had been transformed in the public mind from national treasure to murder defendant. Gone was the dazzling smile and legendary charm of a black man whose race rarely entered any conversation about him. His legend was towering, and he became a beloved figure to all.
Nevertheless, his defence would argue that racism had led police to frame him for a crime he didn't commit.
O.J. and Nicole were once golden, blessed with two beautiful children, living in a world of privilege. Their bitter divorce sent the perfect marriage into the ash heap of failed celebrity unions. There were rumours of domestic violence.
But O.J. Simpson remained a recognizable hero. To his fans he was "The Juice," the nickname he won on the gridiron, where he broke records for running.
And in the summer of 1994, when he ran again in a white Bronco, trailed by slow moving police cars, those who clung to his legend lined the freeways with the familiar phrase scrawled on placards, "Go, Juice!" They were rooting for him to win again.
Some would argue that he did win. After all, he was acquitted. But from hindsight of 20 years, it is clear there were few winners, least of all Simpson.
Contacted through his lawyer, Simpson, who had spoken to me many times over the years, declined to be interviewed for this story. He sent word that anything he said would just result in media attacks and would be detrimental to his children.
In two decades, he has never wavered in his claim of innocence. When both sides had rested after nine months of trial, Simpson told the judge: "I did not, could not and would not have committed this crime."
A civil jury, however, awarded the Brown and Goldman families $33.5 million in wrongful death damages, which the Goldmans are still trying to collect.
Simpson moved to Florida where laws benefit retirees and he could pursue his passion for golf. His private life provided tabloid fodder as he acquired a girlfriend and frequented Miami clubs. A road rage incident sent him back to court but he was acquitted.
In 2007, while in Las Vegas for a friend's wedding, Simpson staged a casino hotel heist of dealers trying to sell his memorabilia. The raiding party included a man with a gun and the entire episode was secretly tape recorded.
Some saw the case as payback when Simpson was sentenced to 9 to 33 years in prison for armed robbery and kidnapping. Others got off with sentences as light as probation.
Two Las Vegas police detectives were overheard on tape saying: "They didn't get him in L.A., but we'll get him here."
At an unsuccessful hearing seeking a new trial last year, Simpson was unrecognizable as the once trim and fit celebrity. He was bloated and greying, his arms and legs shackled to a courtroom chair. His defence continues to appeal as he is held in a Lovelock, Nevada, prison cell.
Deutsch covered three O.J. Simpson trials in Los Angeles and Las Vegas and has interviewed him over two decades.