Researchers have been avidly trying to better understand the delicate relationship between police and the communities they serve and according to a new study of police officers in Oakland, Calif., police are more likely to speak to white people with a higher level of respect than they do to black people.

The study was published Monday in the Proceedings of the National Academy of Sciences Monday. Researchers used 183 hours of body camera footage taken during 981 routine traffic stops by 245 different officers with the Oakland Police Department in April 2014, CNN reports. The footage was transcribed, and 312 utterances spoken to black community members and 102 utterances spoken to white community members were randomly selected by the researchers for volunteers to analyze.

Rob Voigt, a doctoral student in the linguistics department at Stanford University who is the lead author on the study told CNN that at the very least “this provides evidence for something that communities of color have reported, that this a real phenomenon.”

Voigt added that he and his colleagues were grateful to the Oakland Police Department for allowing them to study the department’s body camera footage.

“We’re also hoping it inspires police departments to consider cooperating with researchers more. And facilitating this kind of analysis of body camera footage will help police departments improve their relationship with the community and it will give them techniques for better communication,” he said. “When people feel they’re respected by the police they are more likely to trust the police, they are more likely to cooperate with the police, and so on and so forth. So we have reason to expect that these differences that we find have real-world effects.”

CNN reached out to the Oakland Police Department for comment on Monday. A public information officer responded that department officials and researchers plan to provide comment soon.