A U.K. study of data on more than 30,000 crimes sheds new light on crime after dark, suggesting that the overall risk of crime rises when darkness falls, but that risk varies depending on type of crime and geographical area. Jim Uttley of the University of Sheffield, U.K., and colleagues present these findings in the open-access journal PLOS One on June 25, 2025.
Prior research has shown that darkness reduces people's feelings of safety, and that improved street lighting can help people feel safer being out after dark. However, research on whether the risk of crime is actually higher after dark has produced inconclusive results.
To help clarify the potential influence of darkness on crime risk, Uttley and colleagues analyzed data on 34,618 crimes that occurred from 2010 through 2019 in the South Yorkshire region of the U.K. Some of these crimes were committed at times of the day that, because of seasonal changes, occur during daylight for part of the year but after dark for the rest of the year. This enabled the researchers to test whether crime risk at such times of day is greater during daylight hours or after dark. The researchers also statistically accounted for other potentially influential factors, such as weather and vacation periods.
The analysis showed that, overall, crimes were more likely to occur after dark than during daylight. However, out of fourteen kinds of crime analyzed, only five appeared to be significantly more likely to occur after dark: burglary, criminal damage, personal robbery, bicycle theft, and vehicle offences. Other offences, including sexual offences, arson and shoplifting, did not show this association.
The analysis also showed that the change in crime risk between daylight and darkness isn't uniform across all areas in South Yorkshire, with the risk of crime after dark varying by neighborhood.
The researchers conclude that these findings strongly suggest darkness affects risk of crime. Information from this study could be used to help optimize the potential crime-reduction effects of streetlights and other artificial lighting. However, this study did not account for the presence or absence of street lighting. Future research could assess how such artificial lighting and its characteristics, such as brightness, influence crime risk.
The authors add: "There is an assumption that street lighting helps reduce crime. Evidence in support of this assumption is unclear though. In our research we took a step back and asked whether darkness itself increases crime risk. If it doesn't, the presence or absence of street lighting is unlikely to matter. We worked with analysts in South Yorkshire Police to assess changes in the risk of crime taking place in daylight and after dark, using 10 years of crime data. Our findings suggest darkness does increase the risk of certain crimes, including burglary, robbery and criminal damage. We also found the risk of crime after dark varied by neighborhood. We are now working to understand whether street lighting can reduce the risk of crime after dark, and if it can, how we can maximize the crime reduction benefits of street lighting."
In your coverage, please use this URL to provide access to the freely available article in PLOS One: https://plos.io/4mZNKON
Citation: Uttley J, Canwell R, Smith J, Falconer S, Mao Y, Fotios S (2025) Does darkness increase the risk of certain types of crime? A registered report article. PLoS One 20(6): e0324134. https://doi.org/10.1371/journal.pone.0324134
Author countries: U.K.
Funding: The author(s) received no specific funding for this work.
