University of Missouri at St. Louis criminologist Richard Rosenfeld has had “second thoughts.” Like many academic criminologists, he had pooh-poohed charges that skyrocketing murder rates in many cities in 2015 and 2016 result from a “Ferguson effect” — a skittering back from proactive policing for fear of accusations of racism like those that followed the death of Michael Brown in Ferguson, Missouri, in August 2014.

Now, after looking over 2015 data from 56 large cities, he tells The Guardian that he has changed his mind. Homicides in those cities were up 17 percent from 2014. And ten cities, all with large black populations, saw homicides up 33 percent on average.