Ed Flahavan
Director, Home Affairs, Security and Education
The government has introduced Ronan’s Law, a set of measures restricting online sales of dangerous knives and increasing penalties for illegal sales. The law follows the tragic case of Ronan Kanda, a 16-year-old murdered in a case of mistaken identity with a sword purchased online.
Every young life lost to violence is a tragedy so restricting access to knives seems like a sensible step towards keeping young people safer. So how effective can this type of intervention be? We take a look at some of the data on knives and their availability and what the behavioural science suggests.
What do we know about the knives used in homicides?
If we want to understand how effective knife restrictions will be, we need to examine what kinds of knives are actually used in violent crime. Since 2022 the ONS homicide statistics record this. Sharp instruments are by far the most commonly used method of killing in the UK at 46% of homicides last year.
Source: ONS Homicide Statistics year ending March 2024
Going a layer deeper, we can also look at the type of sharp instruments used. The full breakdown is below. Kitchen knives are used in 42% of cases, while hunting knives, zombie knives and others together makes up 21% with the remainder (37%) being other types of knives or sharp instruments or unknown.
Source: ONS Homicide Statistics year ending March 2024
There’s understandably a lot of focus on zombie knives and machetes. We know that access to different knives is likely to vary a lot. A couple of years ago, we ran a survey to find out just how much this varies.
Who has access to dangerous knives?
We asked a sample of the general population what type of knives they had ready access to. Unsurprisingly, we found that almost everyone had easy access to a kitchen knife. Notable however was that between 9% and 12% of 18-23 year olds had access to a sword, machete or combat knife.
The figure below compares the percentage of people with access to different knives to the percentage of homicides they were used in. Importantly this data is for the whole population and for all homicides, so it’s likely to vary a lot depending on the circumstance of the crime. The knives in gang-related homicides with young victims are much less likely to be kitchen knives than domestic homicides.
Source: ONS and BIT data
Does restricting access actually work?
A common counterargument to knife restrictions is: ‘If someone wants a knife, they’ll find a way to get one.’
A key principle of behavioural science is – ‘If you want to encourage a behaviour, make it easy’. This is consistently effective, but also underestimated by policymakers. Pre-filling forms for people, ‘one-click’ to buy or switching the default on pensions.
Is the opposite also true? Does adding frictions deter people from doing things we want to avoid? There’s plenty of evidence to suggest it can reduce harm:
- Reductions in burglary, violence and car theft: In surveys people consistently think crime is on the rise. But for large categories of crimes the opposite is true. Over the last 30 years, burglary, violence and car theft have dropped by around 90%. Home security, car immobilisers and CCTV are generally seen as the drivers of this.
- Suicide prevention: In 1963, 40% of suicides in the UK were by carbon monoxide poisoning. The removal of carbon monoxide from the gas supply in the 60’s and 70’s led to a dramatic overall reduction in suicides (people didn’t switch to other means). Installing barriers on bridges and other physical changes at suicide hotspots are also effective.
- Increasing friction to access paracetamol: The UK’s limit on pack sizes has led to reduced deaths.
- Gun control and shootings: The US has some of the highest homicide rates and gun ownership in the developed world. Research shows the effect of firearms restrictions on gun homicide.
Taken together, this suggests restricting access to lethal weapons – if successful in reducing the number of them on the street – will keep young people safer.
Should we redesign kitchen knives?
But what about kitchen knives? They’re readily available and the most likely to be used in a homicide.
The idea of banning pointed knives has been raised in recent days. To some it’s an obvious next step to keep young people safe. To others, it conjures up images of trying to cut a steak with a butter knife.
Surely, there’s a middle ground. One piece of research looks at the penetration of different types of knives. As expected a completely blunt safety knife (B) didn’t penetrate clothing at all (see below), but even a fairly standard knife with a slightly rounded tip (C), made an incision about one fifth that of a sharply pointed blade (D or E).
Source: Nichols-Drew et al. (2020)
So even a relatively small change in design can significantly reduce a knife’s lethality, while still leaving it as a fully functional and familiar kitchen tool.
Beyond restrictions: tackling the roots of youth crime
Reducing access and availability of zombie and combat knives and reducing the lethality of those that are readily available, are welcome. We also recognise the importance of deeper drivers of youth violence and that ‘nudges’ are part of – but not the whole – solution. That’s why our projects also work directly with young people.
The Ending Youth Violence Lab is developing and testing new approaches to tackling the root causes of youth violence. For example, last summer over 400 young people took part in the Summer Jobs programme. The programme gave young people short-term paid employment and youth-worker support to avoid getting caught up in violence.
If you’d like to know more about our work, please reach out.
Ed Flahavan, Director Home Affairs and Education, [email protected]
Tom McBride, Director Ending Youth Violence Lab, [email protected]
