Cat Brooks hears firsthand the anxiety in her neighbors' voices when talk turns to the police. She sees the fear in their eyes when a cruiser drives down the street.
Police violence can have a ripple effect on communities, says Brooks, a co-founder of the Anti Police-Terror Project, an Oakland, California-based group working to create a support system for communities of color. It leaves a psychological and emotional toll.
"I see it in the ways rage explodes on the street in response to police terror," Brooks says. "I see it when people don't want to talk to police."
While there's been scant research on how police interactions can affect people's health generally, it is known that African Americans, who are disproportionately affected by police violence, are 20 percent more likely to suffer serious mental-health problems.
Through her work with APTP, Brooks has become a leading advocate for the study of police-related trauma, and the use of any research to inform policy on police practices.
There are other grassroots campaigns fighting for better research around police violence and community trauma. Following the shooting death of 26-year-old Mario Woods by San Francisco police in December of 2015, members of his community formed the Justice 4 Mario Woods coalition with the express purpose of working with academics to study police violence. In May of 2016, the Do No Harm Coalition was founded in response to police violence in San Francisco, with a stated mission of furthering research on this topic. In April, Do No Harm launched a national survey on the health effects of police violence, called the Justice Study, which asks participants about experiences they, their friends, their family, or other people in their community may have had with law enforcement officers.
In 2017, police killed 1,147 people; black people made up a quarter of those killings, despite being only 13 percent of the population. In a rapidly gentrifying area like San Francisco, research shows an increase in the rate of police killings.
"When police behave as judge, jury, and executioner, the community becomes traumatized," says Rupa Marya, co-founder of the Do No Harm Coalition and an associate professor of medicine at the University of California–San Francisco. "That community lives in distrust. Instead of asking if race is causing this, we need to ask how racism on a systemic level is creating dynamics that lead to poor health outcomes."
Census data shows that African Americans are seven times as likely to live in neighborhoods with limited to no access to mental-health services. One study suggests African Americans may experience a form of post-traumatic stress disorder (PTSD) that arises from repeatedly witnessing traumatic events both in person and through social media. What's more, when the cycle of police violence continues, it can trigger pre-existing PTSD.
"It's a very desperate situation," Marya says. "There are very few mental-health resources for those who are enduring trauma, specifically the trauma of police violence. Often there aren't trained professionals to help people manage the trauma."
To address trauma, APTP started a first responders' committee, which conducts independent investigations of police violence as soon as it happens and also provides healing spaces for community members.
"When police kills someone in our community, it's not just a loved one," Brooks says. "That's a triggering and traumatic event for every person in the community. It creates a psychological impact and emotional impact."
Brooks says this trauma can lead to problems like substance abuse, or a failure to perform at work or even in everyday tasks like driving. Brooks gives an example of getting pulled over: "Maybe you forgot to use your turn signal. You may be sober. By the time that encounter [with police] is over, palms covered with sweat, you were covered with tears. That could've been the end of your life."
The effects of police violence extend beyond mental health, Marya adds; it can potentially affect the likelihood of chronic stress, cardiovascular health, and diabetes.
Sonja Mackenzie, an assistant professor in public health at Santa Clara University and a researcher for the Justice Study, has been working on an HIV prevention research project in the Bay Area for the past five years. As a part of the study, she and her colleagues developed a series of questions related to perceptions of law enforcement.
She found that people who witnessed police violence in the past six months, which includes verbal, physical, and sexual harassment, were less likely to engage in HIV reduction behaviors.
"This tells us that the very things we are trying to support communities to do in terms of public-health practices and prevention methods are being negatively impacted by people's fear of being surveilled by law enforcement in our neighborhoods," Mackenzie says.