German Lopez: There are two theories for the Ferguson effect. One is that police have been scared by criticism and are pulling back, and that's leading to more crime. The other is that Black Lives Matter protests have reinforced community distrust, which has boiled over, leading to community members taking the law into their own hands since they can't trust police. Which one of these do you think has more credibility, in light of your research?
Richard Rosenfeld: I find the second somewhat more plausible. But I have to say that we don't have the data yet to fully evaluate them. Well, let me qualify that a bit: We do have the data — the FBI has the data, but it won't release year-end data until sometime next fall.
So we can evaluate the depolicing argument, right? If depolicing is occurring and it comes with pulling back, we should expect arrest rates to be declining in those cities where we've seen very sharp increases in homicide.
Now, there is a paper out of Johns Hopkins [University] that looks at that in the case of Baltimore, and finds a "Freddie Gray effect" in Baltimore — that is, he finds declining arrest rates associated with increases in homicides in Baltimore [after Freddie Gray died in police custody, leading to protests and riots]. In one other city, Chicago, I'm prepared — although we don't have systematic evidence that I'm aware of — to believe that something like depolicing is contributing to more homicide there.
But I don't know that that's the case in any other city.