Knife imagery use: Helpful or harmful?

Image from no knives, better lives of a group of young people socialising
Image courtesy of No Knives Better Lives,  © Open Aye

In this guest blog Dr Charlotte Coleman looks at the impact the use of knife imagery in interventions may be having. While well intentioned, she argues, use of such imagery may actually increase knife carrying and negatively affect the mental health of young people.  Dr Coleman is a forensic psychologist at Sheffield Hallam University, a representative of the Society for Evidence Based Policing and Co-Lead of Preventing, Reducing and Investigating Criminality and Exploitation (PRICE).

By Dr Charlotte Coleman

In intervention campaigns shown on posters, in newspapers, on TV and social media, we see images of knives alongside messages of knife crime desistance to increase awareness of knife crime and the likely consequences. Many organisations feel a responsibility to provide knife crime interventions (e.g. schools, police, local authorities and the third sector), and often include images of knives to help improve attention to the information being presented. Young people can therefore experience multiple intervention/education exposures, both on and offline. Where these exposures include imagery this can increase perceptions of the prevalence knife crime and instil implicit assumptions that ‘they’ are responsible for it (Cogan et al, 2020). Whilst multiple exposures to messaging may provide confirmation and consolidation of key messaging, multiple exposures to knife imagery may be having adverse effects. Researchers are now raising concerns that exposure to knife imagery may increase fears of being involved in knife crime, which may in turn lead to more young people carrying knives for defence.

Large scale experiments have shown that seeing knife images increase young people’s fear of knife crime with 35% agreeing that knife images made them feel scared and more worried about knife crime (Ramshaw & Dawson, 2022), and this effect was greater for those already worried about knife crime. Although not all young people are affected by viewing knife images, specific sub-groups, those who the interventions are most targeted towards, appear to be the ones most affected (Coleman et al., 2022). Those who were already worried displayed more negative responding, and those who viewed knives more favourably displayed more excitement when viewing knife images. For both groups, this may make them more likely to carry a knife, rather than less likely. Importantly the young people themselves did not self-report these changes in perception, suggesting that they were either not aware of their emotional response to the images or were trying to downplay it.

Secker and Braithwaite (2021) found that almost two thirds of young people reported experiencing Secondary Traumatic Stress (STS) from viewing knife imagery on social media, and nearly a third reported Post-Traumatic Stress symptoms. These effects were higher for younger females and those living in towns and villages, and therefore not young people who were more at risk of knife crime. Therefore there is concern that in addition to increasing the potential for defensive knife-carrying, there are also impacts on mental health through the viewing of knife imagery.

There is little evidence that points to positive outcomes from using knife imagery in anti-knife interventions and campaigns. Even using imagery in campaigns to highlight reductions in knife risk can still increase fear, for example Cogan et al, (2021) found that using images of surrendered knives can invoke fear in young people.

 Whether the activity is aimed at informing young people about knife crime risks, how to avoid knife crime, or even to simply report successes in tackling knife crime, using accompanying knife imagery is likely to engender negative emotional responses, that may for some young people, put them at greater risk of mental health issues and of knife crime involvement.

The views expressed in guest blogs and in associated links belong to the authors and do not necessarily represent the views of the SVRU.

Niven Rennie


Telephone: 01786 896785          Email:

Niven has more than 30 years of operational policing experience in the United Kingdom. He joined Strathclyde Police in 1985 serving throughout the west of Scotland in a variety of ranks and positions before progressing to the rank of Chief Superintendent. Niven previously held the role of President of the Association of Scottish Police Superintendents where he represented the interests of the operational leaders of policing in Scotland.

On leaving Police Scotland in 2016 Niven took up the position of Chief Executive Officer of South Ayrshire Escape from Homelessness (SeAscape).

Niven was appointed director of the Scottish Violence Reduction Unit in July 2018.