Matt Apuzzo in The New York Times:

A string of deadly police encounters in Ferguson, Mo.; North Charleston, S.C.; and most recently in Cincinnati, has prompted a national reconsideration of how officers use force and provoked calls for them to slow down and defuse conflicts. But the debate has also left many police officers feeling unfairly maligned and suspicious of new policies that they say could put them at risk. Dr. Lewinski says his research clearly shows that officers often cannot wait to act.