The scientists found that civilian complaints of major crimes dropped by about 3% to 6% during the slowdown.

“The cessation of proactive policing corresponds roughly to the relative decline in crime that earlier research attributed to the effects of mass incarceration,” the authors noted.

The researchers ran the analysis under a couple other models, and the results still held. They examined whether crime underreporting could have biased the findings, and the results still held.

“While we cannot entirely rule out the effects of under-reporting,” the authors wrote, “our results show that crime complaints decreased, rather than increased, during a slowdown in proactive policing, contrary to deterrence theory.”