Objectives <p>This study offers evidence that crime, and specifically violent crime, can be reduced through low-cost policy intervention. I estimate the effects of daylight saving time adoption on Indiana crime and clearance rates and explore the mechanisms by which this policy affects criminal behavior.</p> Methods <p>This study uses agency-level data from the US Federal Bureau of Investigation Uniform Crime Reporting (FBI UCR) program and the April 2006 expansion of daylight saving time in Indiana as a natural experiment to estimate the effects of DST adoption on crime and clearance rate variables.</p> Results <p>The 2006 expansion of DST to all Indiana counties reduced the average total crime rate by 2.3-4.1% and reduced the violent crime rate by 6.3-8.5% but had no measurable effect on clearance rates in the treatment counties during the months in which DST was observed. The reduction in crime rates appears driven by significant reductions in armed robbery, and simple and aggravated assault. The evidence suggests that DST acts to reduce crime rates predominantly through a deterrence channel, with little evidence for an accompanying incapacitation effect.</p> Conclusions <p>These results, if generalizable to other states and months of the year, introduce the possibility that extending DST year-round in the US may be accompanied by socially-beneficial crime reduction effects.</p>