It was my first day of jury service. Our communal room smelt of stale cigarette smoke and the worn intimacy of cloth too long against flesh. The room set me on edge, like a dentist’s waiting room, or the annex where you wait before a job interview — for a job you don’t want. It was a relief to be assigned to a trial, archaically called Regina vs Reid. We were told it involved an alleged sexual assault on a young woman.

I hadn’t thought about that trial, way back in the mid-1990s, until last week when Kirk Reid’s face flashed up on the television with news that he’d been jailed for life for attacking 27 women, including two rapes.

The police, who now believe he attacked more than 100 women, have been criticised for not pursuing inquiries into Reid after suspicion fell upon him in 2001. But Reid could — and should — have been stopped in his monstrous tracks much, much earlier. I know, I was there.

In Regina vs Reid, the victim testified — with a sincerity that was obvious to me — that Reid had been passing her in a narrow alley in Soho when he violently assaulted her, penetrating her vaginally with his fingers. Shocked, but fuelled with the adrenaline of fury, this plucky young woman had given chase. Reid’s one piece of bad luck was to emerge from the dark alley into a head-on collision with a passing policeman, who arrested him after his victim complained of his attack.

Robert Frost, the American poet, described a jury as 12 people chosen to decide who has the better lawyer. Regrettably, it was true in this case. The victim was articulate and succinct; her account of the assault plausible and precise. But the prosecution barrister lacked lustre. His raspy, two-pack-a-day voice was languid with boredom as he plodded through the crown’s case.

The defence barrister, on the other hand, was shrewd and devastatingly persuasive. With the verbal equivalent of sleight of hand, he insinuated that the victim was unreliable, vengeful, unstable and probably a man-hater.

He proceeded purposefully, his confidence as broad as his shoulders. In honeyed tones, he cut through the prosecution’s case like a knife through pâté. When addressing the judge, of course, he adopted the deferential pose of a royal footman. But when talking about the innocence of the accused, he pronounced Reid’s name slowly and reverently, as though rolling some priceless vintage claret around his mouth. The defence barrister had the courage of his convictions — that is to say, he didn’t want his client to get one.

Reid himself looked the picture of innocence, a black man victimised by a racist society and a xenophobic police force. To me, one of the few women on the jury, Reid’s polished charm was negated by his cold, unblinking eyes. His barrister portrayed him as helpful, hard-working and friendly. We now know that the man was friendly in the way that a parasite is friendly. In truth, Reid was a devious, ruthless predator who made most of his attacks on women as they walked home late at night.

Despite the absurdity of Reid's defence — the notion that a young woman of good character, rushing back to work after her lunch hour, would randomly condemn a stranger to the psychological torture and ignominy of a false sexual assault claim — it was hard not to be swayed by the oratory of his counsel.

What about the prosecution? Incredibly, its barrister made no final speech. “See?” said some fellow jurors, before we retired to consider our verdict. “Even the prosecutor does not really believe in his case.”

I discovered later that the Crown Prosecution Service (CPS) guidelines said that its barristers were not obliged to make final speeches in short cases — a rule that is never explained to jurors and that they completely misunderstand. In this country, oddly, it’s a crime for jurors to talk about what goes on in the jury room. But what this means is that prosecutors don’t realise the psychological impact that conduct such as this can have on their case.

Intimidated from the outset by the formal surroundings of the courtroom, the jury looked for guidance to the judge. Richard Gee loomed over us with pompous disdain. He instructed us that there was no evidence of a sexual assault. By this, he meant there was no DNA or evidence of semen. The judge did not remind us that the woman’s testimony was good evidence. He instructed us that a conviction might be unsafe — his heavy, rounded vowels raining down on the unsuspecting female victim like blows.