Seizing military weapons does not increase violent crime nor risk police safety

More local law enforcement agencies are using military equipment, such as tear gas, armored vehicles and rubber bullets, to handle social justice protests—calling into question police militarization.

But if police no longer used weapons and tactics previously connected to the military, there is little evidence that this would impact violent crime or officer safety, according to a new University of Michigan study.

In fact, previous data analyses supporting officers taking on the appearance and using weapons like soldiers as a crime-reduction method are unreliable, said U-M researcher and study author Kenneth Lowande. The data problems also impact studies that claim military equipment make police more violent.

In a report published today in Nature Human Behaviour, Lowande examined the substantial limitations of data used to analyze the effects of transferring surplus military equipment, or SME, to law enforcement.

Federal authorities have subsidized weapons and equipment acquisition, but limitations in record keeping about these transfers have rendered studies of their effects not credible, he said. The current study examined 3.8 million archived federal inventory records to gauge the reliability in these other studies.

During a typical three-month period, more than 15,000 controlled items vanish from agency inventories and more than 4,000 are received for transfer, the study indicated.

Lowande, U-M assistant professor of political science, compared this data to data collected when the Obama administration recalled SME in 2015, which resulted in a forced demilitarization of several hundred police departments. Proponents of SME transfers, as well as the Trump administration, say that demilitarization would lead to an increase in violent crime, but that's not what Lowande found.

"When you examine crime and officer safety statistics in these demilitarized departments and compare them to similar departments that weren't impacted, you find essentially no differences," said Lowande, a faculty associate at the Center for Political Studies at U-M's Institute for Social Research.

"I find little to no evidence that demilitarization had an impact on violent crime or officer safety. Put differently, contrary to the claims of those who support the transfer of equipment, these data do not support the conclusion that militarization saves lives—or that demilitarization risks them."