Knife crime: important new findings could help us understand why people carry weapons

Social media, drill music and middle-class drug use have been variously blamed for the sudden increase in knife-related murders of young people in England and Wales. But not only are these assertions about why people carry knives almost certainly wrong, they are also far too simplistic to explain this complex behaviour.

Despite the great harm that weapons can cause, we only have a very rudimentary understanding of what drives someone to carry one. There is some truth in the idea that people carry knives because they fear being attacked with a knife if they don’t, but that’s far from the full picture. My research shows that weapon-carrying in England and Wales is driven much more by being involved in violence than by fear or past victimisation. I’ve also found that when someone’s peers are involved in crime and when a person distrusts the police, they are more likely to carry a weapon.

It also shows that there is a surprising degree of similarity between young people who carry a weapon. That can help us to better target interventions to prevent this dangerous behaviour.

Finding a pattern

The relatively little research about weapon-carrying that does exist has been done in the US. There are different laws and cultures around weapons there, which means that research may not apply to other countries. In order to better understand why young people in England and Wales carry weapons, I analysed the largest available survey of young people’s offending behaviour and looked for differences between those who had carried a weapon and those who had not.

I found that weapon-carrying was rare – around 4% of 10- to 25-year-olds who were surveyed reported carrying a knife or gun in the year before they were surveyed. The analyses found that the peak age for weapon-carrying was 17 – and being male tripled the risk. People who had a recent history of violence or drug use, who had little or no trust in the police or had lots of peers who had been in trouble with the police were each more than twice as likely to carry a weapon. Compared to these factors, being a victim of violence or feeling that one’s neighbourhood is dangerous were not strongly associated with weapon-carrying – although the actual extent of disorder in the person’s neighbourhood was a good predictor.

The link between carrying a weapon and distrusting the police is an important new finding. While trust of the police is a complex topic, it’s possible that young people who live in high-crime neighbourhoods or who are already involved in crime may not see the police as being able or willing to protect them from harm. In those situations, it is unsurprising that a young person would see carrying a weapon as justified or necessary.

These findings demonstrate that weapon-carrying is a complex behaviour and that it is influenced by factors at many levels: individual factors like a history of violence, interpersonal factors like peer offending and community factors like neighbourhood disorder. Each of these levels exert their own influence on the decision to carry a weapon. Many of the risk factors that have been shown to influence carrying a weapon in England and Wales are similar to the risk factors for carrying a gun in the US. This indicates that there are some common causes for carrying a weapon in different countries, which means that some of the successful interventions that have been used in the US may well be effective here.

It should be said that while this study is based on the largest available survey of young people’s offending, the data were collected between 2004 and 2006 – before Youtube, WhatsApp and Snapchat became popular ways for young people to communicate. It was also gathered before the advent of austerity, which has resulted in dramatic cutbacks to public and charitable services for young people. We don’t know what impact these developments have had on weapon-carrying and other violent behaviours.

The finding that a large amount of weapon-carrying can be explained by a small number of factors suggests that weapon-carriers are quite similar to each other – or at least that weapon-carrying has some common causes. For those working to prevent weapon-carrying, this is useful to know. While some interventions like social media campaigns try to target large sections of the population, these findings suggest resources would be more effectively spent helping young people who exhibit many of the risk factors for carrying a weapon or supporting those people who have already carried a weapon to change this behaviour.

Based on this research, working with peer groups of at-risk young people, rather than individuals, and building trust between these young people and authorities, should yield positive results as part of a long-term public health-informed strategy to reduce youth violence.