By Dominic Casciani
Measures to cut knife crime may not work because nobody knows if the problem is genuinely getting better or worse, experts have warned.
David Nowak: Stabbed in London
A report by King's College London criminologists says attempts to cut knife-carrying are held back by the lack of a "considered, clear strategy".
At least 20 young people have died in stabbings during 2007, with the latest death in London days ago.
The Home Office says figures show that overall violent crime has been falling.
In its research, the Centre for Crime and Justice Studies said it had reviewed what was known about the extent of knife crime in the UK, although predominantly in England and Wales.
It warned that ministers were introducing policies to clamp down on knife carrying without taking into account underlying fear and insecurity.
HOMICIDES AND KNIVES
1997 homicides: 663
37% involving knives
2006 homicides: 765
28% involving knives
Source: Home Office
A key factor was that many carriers were young people who had been previous victims of crime and now believed a knife offered them some safety.
Increased police searches and new powers for teachers to search pupils for weapons are also criticised for fuelling feelings of mistrust.
The report claims last year's knife amnesty, when almost 90,000 knives were handed in, had a "very limited" impact on crime, with millions of knives remaining in circulation.
Knife crime also appeared to be linked to poverty with those living in poor areas, particularly ethnic minorities, the most likely victims.
The team said that there was "insufficient evidence" on the wider extent and nature of knife carrying and predicted that it would be difficult to reduce it without understanding the facts.
Despite a spate of deaths during 2007, it was impossible to tell whether the trend for knife-related violence was genuinely up or down over the long-term.
This in turn was leading to splits in policy-making with the Home Office and police apparently taking different positions, said the report.
"A lack of a considered, clear strategy based on high quality, specific research characterises the government and police approach to the problem of knife-related offences," it concluded.
"Politicians and some police officers clearly hold very different views on the seriousness of carrying knives and how best to respond to knife carrying. This is, in part, explained by the lack of proper research."
A spokesman for the Home Office said it was committed to combating gang-related violence and knife crime through "responsive policing, tough powers and prevention projects".
The Home Office had put £1.75m into 400 local groups combating knife crime, said the spokesman.
"We recently made it an offence to use someone to mind a weapon and new powers to enhance safety in schools," he said.
"Anyone who gets involved in gang-related violence can already expect a longer prison sentence.
"In the New Year we will publish a Youth Crime Action Plan which will focus on tackling victimisation and the overlap between young people offending and being victims of crime as well as prevention and reducing re-offending."
But Roger Grimshaw, research director at the centre, said: "Because knives are a part of everyone's lifestyle, their role in offending tells us something about the tensions and fears in society.
"The available evidence about knife use in offending shows it to be a stubborn problem that requires more attention to the causes of conflict, instead of frantic law-making."