"They're often around here, you can tell them by their baggy trousers and big shirts, and you don't mess with them," said one 13-year-old of Italian parentage, who was born and brought up near the school in Maida Vale, north-west London.
But the Triads that she talked about, in the matter-of-fact tone that other youngsters might discuss a football team, have only the loosest connection with the Chinese underworld gangs of the same name.
The SW Triads, one of whose members stabbed Mr Lawrence as he intervened to try to stop them beating up one of his pupils, William Njoh, 13, are one of many street gangs which have sprung up around London and spread to the suburbs.
In Croydon, at least 100 children are thought to be involved in self- styled Triad gangs, and police have held meetings with teachers to brief them on how to spot members among their pupils. In Green Lanes, north London, they call themselves the Triad Gremlins.
The SW Triads named themselves after the Wo Shing Wo Triads, some of the most feared gangsters operating in Chinatown, central London.
Tony Thompson, author of the recently published book Gangland Britain, said: "The kids are usually quite willing to join. What happens is that kids are getting picked on because they are Chinese so they form a gang to protect themselves against this."
Vietnamese and other youngsters from a Far Eastern background then also join. But although the gangs adopt an Oriental street style to distinguish themselves, many now include black and white teenagers.
Founded for mutual self- protection, the gangs move on to picking fights with rival outfits, theft, extortion from pupils, and occasionally start local protection rackets aimed at shops and restaurants.
Philip Matthews, a Haringey youth worker with experience of dealing with the gangs, said: "Small groups of them will go into shops and restaurants and demand protection money. If they don't pay up they will try to smash a few things."
The baggy trousers and the oversized white shirts favoured by the gangs have nothing to do with the Triads and everything to do with what streetwise Chinese youngsters in London regard as the height of fashion.
The trousers also have the advantage of being able to conceal a machete, a Triad weapon which the gangs favour. William Njoh was treated in hospital for a head wound thought to have been caused by a machete in the attack at St George's.
Mr Lawrence was stabbed with a knife, the gangs' other favourite weapon.
The street gangs have adopted some of the symbols and mythology of the real Triads. Some charge an entrance fee of pounds 3.60 and demand the same amount each week, believing the figures three and six have spiritual significance.
Those who attempt to leave the gangs are required to make payments of up to pounds 360. Those who cannot pay face violence. In Croydon, the windows of the house of one schoolboy who wanted to leave a gang were smashed in, and his parents threatened with knives.
Triad graffiti has been spotted outside schools and senior gang members are sometimes given the nickname Di Lo, which means Big Brother. But only a handful of the older gang members have anything to do with genuine Triads and they are very much on the fringes.
Mr Thompson said: "Some may have vague links with the Triads but they are very much on the periphery. The main gangs find them a bit of an embarrassment because they are used to doing things rather more discreetly.
"They style themselves as Triads but the only ones who may have slight links are some of the 19-year-olds who run some of the gangs of 14-year- olds." Police are keen to play down links to organised crime but admit some teenagers who carry out the recruiting have links to the Triads and try to emulate them.
"It has been quite difficult for the police to deal with because we didn't want to glamorise the whole thing", said Chief Inspector Tony London, youth liaison officer for Southwark, south London.
"We got groups of teachers together to try to explain the situation. Our policy now is to try to persuade people not to get involved because once they are sucked in it is very difficult for them to get out."
School and street gangs have existed for years and fights are nothing new. What has changed is the willingness to use lethal weapons and the fact that stylised violence has become part of their culture.
The real worry is not that the Triads are recruiting in schools but that teenagers are learning organised crime can pay in a world which offers only unglamorous alternatives.
What the law says on knives
Carrying a knife normally results in the offender being charged with one of two offences.
The first is possession of an offensive weapon without lawful authority or reasonable excuse, under Section 1 of the Prevention of Crime Act 1953. This carries a maximum sentence of two years' imprisonment.
The second is carrying an offensive weapon in public, under Section 139 of the Criminal Justice Act 1988. This can result in a fine of up to pounds 1,000.Reuse content