This work demonstrates that body camera footage can be used as a rich source of data rather than merely archival evidence, and paves the way for developing powerful language-based tools for studying and potentially improving police–community relations. Co-author of the study PhD student Rob Voigt explained how the team had used these volunteers' ratings to develop a computer model that could automatically analyse the utterances - searching and scoring subtle linguistic markers that made an officer's language more or less respectful.  Image copyright Getty Images Image caption The researchers used body cam footage in their research 
 
 California police officers speak less respectfully to members of the public who are black than to those who are white, researchers studying body camera footage say. "The task was to come up with a score that quantified respectfulness, so each utterance was rated for politeness, friendliness and how formal or informal it was.
– In a conclusion that some may not consider surprising, researchers have found that police officers are more respectful to white people than black people during traffic stops, according to a study published Monday in PNAS. Ars Technica reports the data for the first major study of US bodycam footage comes from 981 traffic stops conducted by 245 Oakland, Calif., police officers in 2014. Researchers had volunteers rate comments made by officers during the traffic stops in terms of respectfulness and more, per the Los Angeles Times. The BBC reports respectful behavior by officers included apologizing, showing an interest in the person, and saying "drive safely." Disrespectful behavior included asking questions, calling the person "bro" or "man," and using words that have a negative connotation. The study found officers were 57% more likely to use one of the most respectful phrases with white people and 61% more likely to use one of the most disrespectful phrases with black people. For example, white people were more likely to be called "sir" or "ma'am," while black people were more likely to be called by their first names. Officers were also found to be less polite, formal, friendly, and impartial with black people. The race of the officer didn't appear to change things. "These routine interactions are important," researcher Jennifer Eberhardt says, per the BBC. "They're the way most people encounter the police." And if those encounters go poorly, citizens may become less supportive or cooperative toward police. (Another study found expecting trouble from black men starts even before kindergarten.)