I help people use data to reduce crime. Associate Professor at @UCLCrimeScience. Former police officer.

Nottingham and London, UK
Joined April 2009
Matt Ashby retweeted
"The UK has fallen because two years ago someone who had probably never handled a gun before was photographed holding an empty gun the wrong way" Is such a lame outrage chasing pile of tepid nonsense, you'd think the world had run out of things to be upset about.
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This experiment finds a practitioner or global-south researcher without expensive institutional journal subscriptions can only access about 5% of criminology research. Long past time more researchers (especially in the US) got serious about open access. doi.org/10.21428/cb6ab371.bc…
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Useful short summary by @PizaEric of research evidence on the limited effect of CCTV (including automated numberplate recognition cameras) on crime and police outcomes. counciloncj.org/wp-content/u…
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When a temporary speed trap (🇦🇺) appears on phone navigation apps (Waze, Google Maps, etc.), average vehicle speed on that road drops by about 4km/h. One for academics still teaching students that offenders don't make rational choices, I guess. 😉 doi.org/10.1007/s11292-026-0…
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Matt Ashby retweeted
I’ve heard Journal of Quantitative Criminology will soon require opens data/code…which will make it the only journal in the entire field to do so. In late 2026. We should be embarrassed! Complete abrogation of basic scientific responsibility for decades. And seemingly no urgency from the editors of Criminology, Justice Quarterly, Criminology & Public Policy, or Journal of Experimental Criminology. There was an effort to get there from the last two editors of criminology, but the new editors haven’t followed through. Meanwhile, what year do you think the first preregistered RCT was published in the fields flagship journal Criminology? If you guessed 2026 then you win (proud to have authored that one 😁).
Chatting with a friend about ongoing efforts in Economics to use AI to replicate every econ paper ever published. This is scary for individual researchers, of course (everyone lives in fear of a coding error), but clearly good for science. I'd love to see this applied to Criminology, but those journals still don't require authors to post their data or code. 🙄
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Embedding mental-health clinicians in police control rooms (🇺🇸) was associated with a small drop (about 7%) in police deployments to mental-health calls. Seems like this would have been a good opportunity for a randomised controlled trial, though. doi.org/10.1080/0735648X.202…
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Of 812 articles in the British Journal of Criminology (2014–2024), only 0.2% (two articles in 11 years!) used experimental/quasi-experimental methods. (Quasi-)experiments aren't good for everything, but is UK crim research really using the right methods? doi.org/10.1007/s11292-026-0…
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An excellent blog post on some of the challenges of using generative AI tools in policing. As so often, it’s the non-technical issues that are the hardest to work through! Definitely worth your time: stephenrussell996702.substac…
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This paper finds that the chances of a person with a criminal conviction (🇺🇸) being charged with a further crime drops rapidly every year afterward conviction, such that after 10 years they're no more likely to reoffend than the population at large. doi.org/10.1111/1745-9125.70…
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This study finds police officers (🇨🇦) perceive dealing with an armed robbery or violent domestic assault in progress as much more dangerous than driving to an emergency call, even though vehicle crashes are the top killer of cops (in 🇨🇦 and elsewhere). doi.org/10.1080/10439463.202…
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More undocumented immigrants moving into a neighbourhood (🇺🇸) is associated with a small *decrease* in violent crime rates and no change in property crime. More legal immigrants moving to an area isn't associated with changes in violent or property crime. doi.org/10.1080/07352166.202…
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It also argues that AI tools are developing so fast normal crime-prevention structures in policing, government and elsewhere (not to mention academia) won't be able to move fast enough to keep on top of AI crime.
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