Pain of police killings ripples outward to traumatize Black people and communities across US

(The Conversation is an independent and nonprofit source of news, analysis and commentary from academic experts.)

Denise A. Herd, University of California, Berkeley

(THE CONVERSATION) It’s been one year since George Floyd’s murder by a Minneapolis police officer set off the largest protests in U.S. history and a national reckoning with racism.

Beyond the protests, every police killing – indeed, every violent act by police toward civilians – can have painful and widespread consequences.

Each year, U.S. police kill about 1,000 people, which equals approximately 8% of allhomicides for adult men. This risk is greater for Black men, who are about 2.5 times more likely to be killed by the police than white men.


The effects of these killings ripple from the individual victim to their families and local communities as they cope with the permanence of injury, death and loss. People victimized by the police have demonstrated higher-than-usual rates of depression, psychological distress and even suicide risk.

But the pain doesn’t stop there.

Public health research I am conducting with my research team at the University of California, Berkeley finds that the harm from police killings of Black people goes beyond the people and places directly involved in these incidents to affect Black Americans far from the site of the killing, who may have never met the victim.

Evidence shows that Black Americans across the U.S. experience police killings of other Black people as traumatic events, and that this trauma diminishes the ability of Black communities to thrive.

The ripple effect

One of the key studies illustrating this ripple effect of police killings on the mental health of Black Americans was published in the medical journal The Lancet in 2018.

Boston University researchers surveyed 103,710 people in the U.S. to measure the relationship between police killings and Americans’ mental health.

Among survey respondents, each police-related fatality of an unarmed Black person in the state where they lived was associated with an increase in the number of days when they reported poor mental health relating to stress, depression or emotional issues.

The authors estimated that the cumulative impact of U.S. police killings of unarmed Blacks could add up to 55 million additional poor mental health days for the U.S.‘s 44 million Black people.

Police killings of armed Black people did not elicit the same distress among Black Americans. And white Americans suffered no additional poor mental health days, as defined by the researchers, after exposure to police killings – no matter the circumstances or race of the victim.

The authors speculated that historical and institutional patterns of systematic, targeted violence against Black people – combined with a general lack of legal consequences when police officers commit such crimes – make the killings of unarmed Blacks particularly stressful for Black Americans.

“Racism, like trauma, can be experienced vicariously,” they concluded.

A 2021 study substantiates the Boston University’s mental health findings.

Scouring emergency department admission records in 75 counties in five U.S. states, researchers found that within three months following a police killing of an unarmed Black person in the county in which they reside, Black Americans sought treatment at local emergency departments for depressive symptoms 11% more frequently than in other months.

Prenatal and childhood trauma

Black women experience acute fear that their children will be harmed by the police.
Those who expressed beliefs that Black youth are at higher risk for having negative police experiences were 12 times more likely to report symptoms of depression during their pregnancy than other women, according to one study from 2017.

Depression during pregnancy can increase the risks for health problems for both parent and child, including newborns with low birth weight or premature delivery – both major causes of infant death. Depression during pregnancy also puts new mothers at higher risk for postpartum depression, which may negatively affect their ability to nurture their children.