A protester raises her hands while blocking police cars in Ferguson, Missouri, November 25, 2014. Adrees Latif / Reuters

The so-called “Ferguson Effect” might exist, just not in the way some have been defining it. Coined by a police chief in St. Louis and popularized by writer Heather Mac Donald, the term describes the idea that “violent crime is up in many American cities because officers are backing off of proactive policing.” The phenomenon has been linked by FBI director James Comey to apprehension on the part of police officers to enter areas they consider hostile or dangerous. Wikipedia offers up this definition:

The Ferguson effect is the idea that increased scrutiny of police following the 2014 shooting of Michael Brown in Ferguson, Missouri has led to an increased murder rate in major US cities.

So, which is it? Are police neglecting their sworn duty to protect or are citizens scrutinizing their methods more?

Two sets of data released this week suggest that neither may be a sufficient explanation. They point, instead, to an alternative: That citizens in black neighborhoods are losing confidence in police.

Three sociologists who studied over 800,000 911 calls in Milwaukee concluded that following a publicized death of a black man at the hands of police calls to the emergency dispatch dropped precipitously, especially in black neighborhoods. “High-profile cases of police violence against unarmed citizens can undermine the legitimacy of legal authority,” they wrote.

Pew Research Center also released a report Thursday that looks at the “racial confidence gap” in how police officers are perceived by the general public. Researchers concluded that whites, blacks, and Latinos show some level of criticism about the performance of their police force, with only 26 percent of all respondents saying they “have a lot of confidence” in the police. The low confidence is most pronounced among blacks. Only 14 percent have a lot of confidence, and they “are about half as likely as whites to have a positive view of the job their local police are doing,” per the report. They are also 25 percent more likely than whites to link the deaths of blacks in interactions with police to a broader society-wide problem instead of viewing each as an isolated incident. By comparison, a third of Latinos have a lot of confidence in police.

Are highly publicized incidents of police brutality and police shootings making black Americans less likely to reach out to police? Do residents of affected communities fear calling 911 to report crimes? Might the fear of a situation ending tragically prevent even people who might be in some danger from involving their local police force?

The Pew report offers some insight into these hard-to-answer questions. Three quarters of white respondents rate police work as “excellent” in terms of using the “right amount of force for each situation.” Only a third of blacks share this view, and two thirds say the police do only a “fair or poor job” in this regard. Among Latinos, two thirds say police are doing “at least a good job,” while just over a third rate them as “only a fair or poor.”

Those numbers reflect both broad-based concern, and its concentration in the black community. As the sociologists noted in their examination of 911 calls, history and research suggest “that African American communities would be more affected than white communities” by police shootings and other incidents of brutality.

Frank Jude was brutally beaten by off-duty police officers in Milwaukee, but his story did not become known for months. Following news reports in a local paper, demonstrators organized to pressure authorities to bring the officers involved to justice. The study looked at 911 call patterns during the year prior to the story breaking and the year following. They chronicled a stark correlation: “We estimate that the police beating of Frank Jude resulted in a net loss of approximately 22,200 911 calls reporting crime the year after Jude’s story broke.” Over half of the total decline came from black neighborhoods.

The racial confidence report from Pew offers some sobering numbers that help put the conclusions in the Milwaukee study into a national context. Only a third of blacks say police do an “excellent or good job” in treating racial or ethnic groups equally, compared with three quarters of whites. Just under a quarter of blacks say the local police does “only a fair job” and about forty percent say they “do a poor job.”

And it’s not just the initial incidents; blacks report a lack of confidence in the ability of law-enforcement agencies to police themselves. Only a third of blacks in the Pew report say police are doing a good or excellent job in “holding officers accountable when misconduct occurs.” But 70 percent of whites say the same. This lack of confidence seems to be exacerbating the historical mistrust experienced by black residents. About 80 percent of respondents in the Pew report believe “these deaths signal a larger problem between police and the black community.” Just 54 percent of whites and 66 percent of Latinos say the same.

Neither of the studies links this lack of confidence to upticks in crime in the areas in which it’s concentrated. But they do suggest that well-publicized incidents are reinforcing historic distrust, and that this deters citizens from contacting police to report crimes. And given the reliance of police on their relationship with local communities, they raise the possibility that the problem in cities grappling with rising crime may be less that officers subjected to scrutiny are backing off from proactive policing, than that communities subjected to repeated abuses are losing faith in those who are sworn to protect them.

This article is part of our Next America: Criminal Justice project, which is supported by a grant from the John D. and Catherine T. MacArthur Foundation.