A team of UC Berkeley and UCSF researchers found that unarmed Black men are at an increased risk of being fatally shot by police based on age and mental illness status in the United States.

The researchers analyzed data compiled by The Washington Post, which detailed 3,090 fatal police-involved shootings between 2015 and 2019 and examined the relationship between race and armed status in these shootings.

Researchers found that Black men above the age of 54 are five times more likely to be unarmed in a fatal police shooting compared to white men in the same age group. Among those above age 54 in the sample studied, 11% of Black men compared to 2% of white men were unarmed when killed by the police.

According to Marilyn Thomas, lead author and postdoctoral fellow at the UCSF School of Medicine, these results were “staggering.”

“When you account for all the factors that contribute to police killings, we should see no racial differences,” Thomas said. “So there’s a theme here. There is some anti-Black sentiment, discrimination or bias that is disproportionately impacting Black men.”

Thomas added that another significant finding of the study was that among those showing signs of mental illness, 12% of Black men versus 5% of white men were unarmed when killed by the police.

According to Thomas, these results suggest that when compared to white men, Black men showing signs of mental illness are almost twice as likely to be unarmed when killed. She added that individuals showing signs of mental illness have a higher chance of experiencing excessive force during a police encounter.

Black men showing signs of mental illness are also more likely to be arrested when encountering the police than to receive necessary mental health intervention, according to Thomas.

“The study provides scientific evidence of what we have been seeing with our own eyes — systematic bias in use of force against blacks,” said study co-author and campus public health associate professor Amani Allen in an email.

Allen added that in recent years, the police have used escalation tactics, rather than de-escalation strategies, particularly in communities of color.

According to the study, Black men also had a notably high risk of being armed when shot by police in the Midwest, a region with a high white population density. In the Southern region, Black men had a much lower risk of being armed when killed, and these results could be attributed to the Southern region’s high Black population density.

“The killing of unarmed people in general is a public health issue,” Thomas said. “But the disparities that we see, these racial inequities, are a public health crisis.”