The authors compared their findings with increases in violence following the August 2014 death of Michael Brown in Ferguson, Missouri. Homicides in large cities rose by nearly 22 percent from 2015 to 2016, and analysts attributed the increase to what is called a "Ferguson Effect."

The two-part "Ferguson Effect" provides a potential explanation for the increase in homicides last year. First is "de-policing," or law enforcement stepping back in "fear they will be unfairly scrutinized" and potentially lose their jobs. The effect's second part maintains "de-legitimizing," or that "breached trust" and lack of confidence urged communities to pull back from relying on the police. The latter makes criminal investigations and resolutions more difficult, according to the study.