When a police officer stops a Black driver, the first 45 words said by that officer hold important clues about how their encounter is likely to go.
Car stops that result in a search, handcuffing, or arrest are nearly three times more likely to begin with the police officer issuing a command, such as "Keep your hands on the wheel" or "Turn the car off."
That's according to a new study in the Proceedings of the National Academy of Sciences that examined police body-camera footage of 577 routine car stops involving Black drivers.
Eighty-one of these stops ultimately involved searches, handcuffings, or arrests. That kind of outcome was less likely when a police officer's first words provided a reason for the stop.
"The first 45 words, which is less than 30 seconds on average, spoken by a law enforcement officer during a car stop to a Black driver can be quite telling about how the stop will end," says Eugenia Rho, a researcher at Virginia Tech.
Amid the recent high-profile killing of Tyre Nichols and other Black motorists after traffic stops, the findings offer a grim sketch of how police stops can escalate and how Black men recognize the warning signs.
Rho and her colleagues focused on Black drivers because this group is stopped by the police at higher rates and are more likely to be handcuffed, searched, and arrested than any other racial group.
"The car stop is by far the most common way people come into contact with the police," says Jennifer Eberhardt, a social psychologist at Stanford University. "With the spread of body-worn cameras, we now have access to how these interactions unfold in real time."
All of the stops in this study occurred in a racially diverse, medium-sized U.S. city over the course of one month; the researchers won't identify the city for privacy reasons.
"The vast majority of the stops that we're looking at are stops for routine traffic violations, not for other things that are more serious," says Eberhardt.
The scientists controlled for factors such as the officer's gender and race, as well as the neighborhood crime rate. About 200 officers were involved in these stops.
"It's not really a function of a few officers driving this pattern," says Rho.
The words or actions of the person behind the wheel of the car didn't seem to contribute to escalation.
"The drivers are just answering the officers' questions and explaining what's going on," says Eberhardt. "They're cooperative."
To understand how Black men perceive the initial language used by police officers during a car stop, the researchers asked 188 Black men to listen to recordings of the opening moments of car stops.
It turns out, perhaps not surprisingly, those Black men were highly attuned to the implications of a police officer starting an interaction with a command.
"When officers began with orders without reasons, Black male participants predicted that the stop would escalate in over 84% of those cases," says Rho.
And even though none of the stops in this study involved the use of force, Black men worried about the possibility of force 80% of the time when they heard a recording of a law enforcement officer issuing a command without offering a reason.
"In this country, we know much more about fearing Black people than the fears of Black people," says Eberhardt. "Many Black people fear the police, even in routine car stops. That fear is a fear that could be stoked or set at ease with the first words that an officer speaks."
Eberhardt notes that millions of people know about the killing of George Floyd in May of 2020 after police officers pulled him from his car, but far fewer people know what happened in the first moments when he was approached by an officer.
"We analyzed the first 27 seconds of Floyd's encounter with police on that day. And we found that Floyd apologizes to the officers who stand outside his car window, Floyd requests the reason for the stop, he pleads, he explains, he follows orders, he expresses fear," she says. "Yet every response to Floyd is an order."
From the very beginning, police officers issued commands without giving Floyd an explanation — the same linguistic signature associated with escalation in this study.
Tracey Meares, a Yale Law professor and a founding director of the Justice Collaboratory at Yale Law School, reviewed this study and says she found it gratifying to see this kind of social dynamic measured with such precision.
"It's hard to deny then," she says, noting that some communities are rethinking whether they want armed law enforcement to be involved in traffic violations.
"There are stark racial differences in who is stopped and who's not," says Meares, who points out that in the one-month period covered by this study, the city's police officers did 588 stops of Black drivers and only 262 stops of white drivers.
Over 15% of Black drivers experienced an escalated outcome such as a search, handcuffing, or arrest, while less than 1% of white drivers experienced one of those outcomes.
"They're not drawing any conclusions from that, but these are things we should just be paying attention to," says Meares. "It strains credulity that there are that many more traffic violations."
Rho says in planning this study, they had initially set out to look at patterns related to traffic stop escalation for white drivers too, but realized that it happened so infrequently for white drivers that there just weren't sufficient numbers to even include them in the analysis.
