Cardiff cut street violence by piping hospital ER data to police

Jonathan Shepherd, an oral and maxillofacial surgeon, spent his career reconstructing the faces of Cardiff's assault victims and noticed a pattern police never saw: most of the young men he treated for bottle and glassing injuries had never reported the attack.

The conventional fix was to get victims to report more, which decades of campaigns had failed to move. Shepherd's problem wasn't a shortage of violence data — it was that the data lived in the wrong building. Every stabbing, glassing and beating that mattered clinically already walked through a hospital's front door with a location, a time and a weapon attached to it, recorded for treatment purposes, in a building nobody had thought to ask.

Piped anonymized ER intake data—location, time, weapon—to police monthly, making hospitals the sensor for violence, capturing assaults that never reached a crime report.

Hospital intake forms record assault details regardless of victim reporting, capturing unreported violence.

Anonymizing data protects victims, so hospitals can share without breaching trust or privacy.

Police overlay this data on their maps, revealing true hotspots and enabling targeted patrols and licensing actions.

When the data you need is unreported, find an institution that already collects it for another reason and route it to decision-makers.

Violence-related hospital admissions roughly halved and violent crime fell about 42 percent in Cardiff between 2002 and 2013. Renamed the Cardiff Model for Violence Prevention, it won the 2008 Stockholm Prize in Criminology and was formally adopted by police forces and health systems in Australia, the Netherlands, South Africa and several US cities and counties, with the CDC endorsing the approach nationally.