The stabbing occurred when Geordie approached Paul when he was begging with his girlfriend Wendy in Soho. Although Paul was charged with murder, both the police and the homeless testified that Geordie was a notorious mafia "brother". The jury found Paul had acted in self-defence and he walked free. Since then, three more "taxmen" have been beaten, bottled and forced into hiding, and now tend to work the fringes of Hyde Park and Marble Arch. "I turned it into a battle," says Paul, now 25 and working at the Big Issue. "It's a street problem and the street is dealing with it."
These are some of the problems that the housing charity Shelter is highlighting in its homelessness awareness week. They are the same problems that Sergeant Susan Hellewell of the Charing Cross Homeless Unit faces. There's the violence - last year, a report by Crisis found homeless people 150 times more likely to be fatally assaulted than the rest of the population - and there's the street instinct to follow its own codes. The only one of its kind, the unit was established 18 months ago to police crimes committed by and against the homeless.
At rush hour each evening,Hellewell and her seven-strong team step out of the station on to the Strand to patrol through the night. Clad in black leggings and high heels, with a blonde bob and the palest eyes, Hellewell has the kind of glamour the casting directors of The Bill would die for. She knows every rough sleeper, every shadow in every doorway. She knows where they've come from and what they're doing, who's vulnerable and who's violent.
The unit can tell the homeless where to get their teeth treated or their feet examined. It has reunited runaways with their families, plucked prison escapees from West End pavements, and put "taxman" Robbie Noonan behind bars for robbing a beggar with an imitation gun. To police the homeless, the unit is learning the laws of the street.
Tonight, Hellewell goes to Charing Cross underground, weaving through commuters to chat with a Big Issue vendor who tells her about Little Paul, another vendor who was robbed last week and had acid thrown in his face. Little Paul won't say who did it. "A lot of the homeless still mistrust the police. The worst crime of all is being a grass," admits Hellewell. "But we're building relationships, so that the street does tell us things."
"The street" is more willing to tell some things than others. "If a 13- year-old is out there, we can go around with a photo and they'll tell us where the kid is," says Hellewell. "That's not considered grassing. A lot of them are entrenched in this way of life, and they don't want more young people going that way."
Hellewell is also kept informed about new faces. "We've found people wanted for rape and attempted murder in doorways. They think if they sleep rough, they'll find anonymity. But the homeless don't want people like that in their community. If someone on the street is a persistent sex offender, they want to know about it."
Along the Embankment, Hellewell spots a lone figure slumped in the stairway of an empty office with a can of Special Brew. She introduces herself, then says she hasn't seen him around before.
"That's because I'm not homeless," he replies, quickly, nervously.
This is a funny place to hang out, Hellewell remarks. The man, who calls himself James, explains he used to sleep rough, and has come back to visit. He admits to a criminal record for robbery but when Hellewell checks, no record is found. "James" must be lying about his name, though he insists there must be something wrong with the computer. "Honest, that's my name. I'm not wanted for anything, I'm just sitting here keeping clean."
It feels suspicious but Hellewell leans on the wall and laughs. "Well mate, I'm not happy. But if you've had us over, you'll be back," she says. James gets up to leave, also laughing. "Makes a change," he says. "Most of the police are just really nasty people."
Homeless charities agree Hellewell's unit is transforming the relationship between police and the homeless. "It used to be based on mutual suspicion," says Ian Brady, deputy chief executive of Centrepoint, a charity for the homeless. "But this unit gets to know homeless people. It's about protection and crime prevention, not heavy-handedness. They should be doing it across the capital and all over the country."
But there are still crimes which the homeless prefer to police themselves. Wendy, a 23 year old from Birkenhead who sells the Big Issue in Covent Garden, calls it street etiquette. "If you're on the streets, you know who's clipping and who's dealing and you don't grass," she says. "In return, they won't do it near you. If you're selling the Issue, nobody will come up behind you and start begging or dipping on top of your business. It's about respect. Street workers stick together."
Some street workers are also keen to take on the "taxmen", and now talk about tracking down the remaining mafia, rumoured to be based in Kentish Town, for a "free-for-all". Paul Egerton explains why he still wouldn't turn to the police.
"We know the Homeless Unit are on our side but there's not much they can do," he says. "To make an arrest, they need victims who will speak in court. And even then, the judicial system might mess up. At my trial, they spent 15 minutes reading out Geordie's previous convictions. He'd stabbed someone in the stomach, hammered someone on the head, and he was still loose. There's no point getting known as a grass just to put someone away for a few months. They'll be back and they'll be after you."
Hellewell is aware of the vigilantes, and she's obliged to caution them. "We know the leaders who want to do take the law into their own hands. And if we see them trying, we arrest them. We know who the taxers are. All we can do is keep on at people to trust us until we get a result."
Even Hellewell admits there are times when she feels a sweet sense of justice as she sees the street in action. Heading through the dark back to the station, we pass Temple tube, where the older homeless congregate, and she tells me about Harry.
"Harry was an old boy who'd lived rough for years. Everyone loved him and looked out for him, but one night, he got his wallet pinched. Everyone knew who did it, so I arrested the bloke, a horrible bloke. But Harry was a useless victim. He just said, `Maybe it was him, maybe it wasn't', so I had to let him go.
"But this bloke had broken the code. It may be all right to rob a suit walking back from some smart job in the city, but not an old geezer who fought in the war. I heard he got a smack, was ostracised, and I haven't seen him for ages. Yes, there is a code. Thank God for that."