Note: The Durham Police Department is scheduled for a routine accreditation by CALEA, the Commission on Accreditation for Law Enforcement Agencies. The public can comment at an information session on Tuesday, March 22, at 6:30 p.m. in the second-floor committee room of City Hall. The public can also comment by phone on Monday, March 20, from 3 to 5 p.m.: 919-560-4594.

When RTI International and the Durham Police Department released data yesterday about racial disparity in traffic stops, the conclusions were not news to most of the city’s black residents.

At public forums, before City Council, and privately, among neighbors and friends who have story after story to tell, the RTI study proved — again — what most of us either knew or suspected: That there has been significant racial bias in traffic stops in Durham. 

Several aspects of this study, though, are different from previous analyses cited by other groups, which compared stop data by race against the racial make up of the overall city population. (RTI noted that approach is “insufficient to reliably identify racial disparity in traffic stops.”)

As important, though, the study exposed the gaps in the data that prevented DPD, the city and the public from honing in on the officers who are responsible for racially disproportionate stops. And while not part of the study, the subtext of its conclusions is that without public scrutiny, none of this may have ever come to light.

RTI, based in Research Triangle Park, analyzed DPD data of 151,700 traffic stops conducted from January 2010 to October 2015 — under the watch of then-Police Chief Jose Lopez. The study concluded there was a “Veil of Darkness” effect within DPD: Essentially, during the day, when it is easier for officers to determine a driver’s race, black drivers were more likely to be stopped by DPD. Black males were particularly at risk: Their odds of being pulled over by DPD were 20 percent higher during the day than at night.

RTI found no similar “Veil of Darkness” bias in Raleigh, Fayetteville or Greensboro.

The largest disparity between day and night stops occurred in 2012. That year, there was a 61 percent chance that the driver was a black man during daylight stops compared with 54 percent chance at night.

Yet, it was not the traffic patrol, but the HEAT unit, which focuses on drugs, vice and violent crime that was responsible for these stops. When these officers made a stop during the day, the odds of the motorist being black was 44 percent higher than a stop made at night. Factor in gender — male — and the odds increased to 76 percent for a daytime stop versus 69 percent for nighttime.

That the HEAT unit is making these stops is especially disturbing because of the nature of its work: Dealing with often highly volatile situations in which a clear-headed, unbiased response can be a matter of life and death. 

However, several key conclusions couldn’t be made because of a lack of data. From 2010-2014, there was a dearth of location information regarding the stops, which RTI called “problematic.” Without that information, RTI could not whether the racially disproportionate stops were occurring in particular districts or throughout the city in general. Nor was there sufficient information about the length of stop and the outcome — whether a driver was arrested, ticketed or merely warned.

The department is now required to keep more detailed data, after public complaints prompted several reforms within DPD. Although it’s difficult to definitively establish a cause-and-effect, public scrutiny of DPD appears to have worked.  RTI noted that the rate of racially disproportionate stops declined in 2014-2015. While RTI drew no conclusions for this decrease, it was precisely these years when citizens’ groups and social justice advocates demanded that city officials — the mayor and city manager, the Human Relations Commission and the Civilian Police Review Board — to scrutinize the behavior of DPD.

At the time, then-Police Chief Jose Lopez denied racial bias existed within DPD, and essentially dismissed community concerns. But after the city intervened, DPD was required to collect more data, more regularly, and publicly disclose them. 

The Human Relations Commission decided that despite Lopez’s assertions, racial bias was present at DPD. Other changes, such as written forms for consent searches, were put in place — although there are still questions about the rate of probable cause searches.

Last fall, Lopez resigned under pressure from his boss, City Manager Tom Bonfield. (Bonfield did not hire Lopez; now-City Attorney Patrick Baker brought Lopez on in 2007.)

Since December, Interim Police Chief Larry Smith, a 27-year veteran of DPD, has led the department. Publicly, anyway, Smith has inspired more confidence than his predecessor. He does seem less defensive and more transparent, for example, providing the public with more fine-grained data last month in DPD’s 2015 fourth quarter crime report.

After 18 drafts — literally — the Council walked back the general order on body cameras over civil liberties and transparency concerns; Smith complied, and without the protestations that characterized Lopez’s administration.

As for the study, Smith and DPD initiated it to evaluate if any policy changes are alleviating the problem of racial bias.

“This is a study that the Durham Police Department requested to determine the possibility of bias being a factor in our traffic stops and examine if the changes we’ve put in place sufficiently addressed those concerns,” Smith said in a DPD press release. “It’s essential that we get an objective view of our operations and in turn be willing to not only accept the findings, but continue to work toward putting the necessary tools in place to correct the issues this analysis revealed—and ensure that bias of any kind is never a part of police operations.

“We believe the improvements in the disproportionality are a result of the changes in our policies, procedures and training that we’ve instituted in the past few years. This shows that we are willing to listen to our community and make adjustments in our policing practices when necessary,” Smith said.

When more data become available, hopefully Durham will have a better handle on what’s happening, where. Nationwide, we already know how biased policing can damage minority communities, jailing black men — or worse — upending families, and by extension, perpetuating generational poverty. With that as a backdrop, building police trust with minority communities could take years.