When a man is stabbed to death on Oxford Street in Central London, the concern bordering on alarm is destined to be felt much further afield than the immediate vicinity. For this is not a little-known road in a London borough but Britain’s busiest shopping street, known around the world.

The sixth fatal stabbing in London this month has led to renewed fears that knife crime is growing nationwide. But its prevalence is difficult to measure because only since April last year have figures for attempted murder, serious wounding and robbery involving knives and other sharp instruments become part of published police statistics.

What information is available shows that while the number of knife killings has risen, the proportion of homicides caused by a sharp instrument has remained stable over the past 11 years.

Thirty-three per cent, or 197, of the 586 homicides in 1996 were with a sharp instrument – mostly assumed to be knives – compared with 35 per cent, or 258, of the 734 homicides in 2006-07.

Figures from the British Crime Survey, which interviews 47,000 people aged over 16 about their experience of crime, also suggest that the proportion of violent crime involving knives is broadly stable and in some areas may have fallen.

An estimated 7 per cent, or 168,000, of 2.4 million violent incidents in 2006-07 in England and Wales involved a knife, compared with 8 per cent, or 324,000, of 4.05 million violent incidents in 1996.

Of 392,000 muggings in 2006-07, 16 per cent ( 62,720) involved a knife, compared with 22 per cent (85,800) of the 390,000 muggings in 1996. Of 894,000 incidents of stranger violence in 2006-07, 5 per cent (4,700) involved knives, compared with 4 per cent (38,000) of 950,000 incidents of stranger violence in 1996.

These figures must be treated with caution, however, because the British Crime Survey does not interview under16s, and those carrying out the survey struggle to penetrate poor inner cities, the areas affected most by crime. As a result, although the survey offers a more complete picture of crime than police records of offences, it is likely that it underestimates the true extent of knife crime.

Carrying a knife is the most common form of knife-related offending. A Home Office survey of 5,000 people aged 10 to 25 in 2005 found that 4 per cent had carried a knife in the previous 12 months and carrying knives was most common among 16 and 17-year-olds.

Eight out of ten of those who had carried a knife said that the main reason was protection, and fewer than one in ten said that they carried the weapon to threaten someone.

Alf Hitchcock, Deputy Assistant Commissioner of the Metropolitan Police, said: “Statistically knife crime remains a rare event. However, there are two trends that have been observed over the last few years: the severity of injuries sustained through knife crime has become more serious; and the age of offenders and victims has decreased from mid teens to early twenties, to early to mid teens.”

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