Militarizing police forces does not reduce crime or make police officers safer, according to a study published recently in the Proceedings of the National Academy of Sciences.

“On average, militarized police units do not appear to provide the safety benefits that many police administrators claim,” said Jonathan Mummolo, Assistant Professor of Politics and Public Affairs at Princeton University, the study’s author.

The results of Mummolo’s research may not seem surprising, but they directly contradict the assertions of law enforcement officials across the country, from the local to the federal level.

After police responded to the 2014 protests in Ferguson, Missouri with assault rifles and tanks, Col. John Belmar, the top police officer in the county, claimed that military equipment had kept civilians and officers safe during the protests. “Had we not had the ability to protect officers with those vehicles, I am afraid that we would have [had] to engage people with our own gunfire,” Belmar told USA Today. “I really think having the armor gave us the ability not to have pulled one trigger.” If the armor was necessary to prevent the police from firing, one wonders why they carried assault rifles in the first place.

At a 2016 press conference, Democratic Mayor Bill de Blasio announced that New York City would be providing $7.5 million worth of military helmets and vests to its police force. “An attack on our police officers is an attack on all of us,” he said. “And we have to make sure we’re taking every measure available to protect our officers with the latest gear, the latest technology, given the horrible scourge of guns in this country, and how we’ve seen these guns turned against law enforcement.”

Militarization of the police started in the 1990s under the Department of Defense’s Program 1033, which provides surplus military gear to federal, state, and local police under the guise of the War on Drugs. Examples of this war-making equipment included grenade launchers, armored vehicles and bayonets. These armaments flowed steadily to the police over the decades, with more than $5 billion in surplus gear transferred to date.

People around the world were shocked and outraged at the brutal response to the protests in Ferguson, and by the way that the police force had been transformed into an occupying army. As part of an effort to ease popular anger, the Obama administration slightly restricted, but did not eliminate, police departments’ ability to obtain surplus military gear.

“Those restrictions went too far,” said Attorney General Jeff Sessions when he addressed the 63rd Biennial Conference of the National Fraternal Order of Police last August. “We will not put superficial concerns above public safety.” Any reservations about turning police into soldiers who fight battles against citizens were thus “superficial,” in the eyes of the Trump administration. Sessions described the weapons as “life-saving gear” that are needed to fight “terrorism” and “crime.”

Mummolo’s research shows that such talk is no more than a pretense. For his research, he defined police militarization as “a continuum defined by a combination of equipment, tactics, and culture that centers on violent conflict.” It is difficult to categorize certain localities as militarized because the degree of militarization varies from place to place. Mummolo overcame this difficulty by focusing on special weapons and tactics (SWAT) teams, which are modeled on military special forces units and represent “a heightened commitment to the use of militarized equipment and tactics.”

Through a public records request, Mummolo obtained information about every SWAT deployment in Maryland over the five-year period from fiscal 2010 through fiscal 2014. Maryland agencies had recorded all SWAT activity uniformly because of a state law, since expired, that had required them to do so. There were approximately 8,200 SWAT deployments during the period that Mummolo studied.

To determine the extent to which police militarization affects crime and officer safety, Mummolo combined data from the federal Census of State and Local Law Enforcement Agencies surveys (which describe whether agencies provide SWAT services) with FBI data on violent crimes and the FBI’s Law Enforcement Officers Killed and Assaulted database.

Mummolo found that, far from fighting violent crime or terrorism, the purpose of approximately 91 percent of SWAT deployments was to serve search warrants.

Deploying a SWAT team for this purpose is to apply excessive and overwhelming force. The operation “often involves percussive grenades, battering rams, substantial property damage, and, in rare cases, deadly altercations stemming from citizens’ mistaken belief that they are experiencing a home invasion,” said Mummolo.

Less than 5 percent of deployments were responses to “barricade” scenarios, which involve an armed suspect who refuses to surrender to police. The data “show that the vast majority of SWAT deployments occur in connection with nonemergency scenarios,” said Mummolo. The soldiers-policemen enter homes forcibly in 68 percent of deployments and seize property in 84 percent of deployments. This shameless brutality can have no purpose other than terrorizing the working class.

The demographic makeup of Maryland’s localities varies in racial diversity. Mummolo found that the higher the percentage of black residents in an area, the greater the volume of SWAT deployments per 100,000 residents in that area. This correlation persisted after Mummolo controlled for local unemployment, education, household income levels and local crime rates. The data confirm that SWAT teams are used to attack the poorest layers of the population.

When he examined the data to evaluate the effect of a department’s use of a SWAT team on violent crime, Mummolo concluded that “there is no evidence that acquiring a SWAT team lowers crime or promotes officer safety…. Using the available data, the benefits of increased deployments [on crime and officer safety] appear to be either small or nonexistent.” These findings expose the claims of Belmar and Sessions as fraudulent.

The study uses its results to also suggest that if only greater care is taken by the authorities in the deployment of military gear, police-community relations will benefit. “…[P]olice may suffer reputational damage when they deploy militarized units,” said Mummolo. “These results suggest that the often-cited trade-off between public safety and civil liberties is, in the case of militarized policing, a false choice.” In other words, the aim is to convince the authorities to proceed with more caution as they continue their campaign to defend the status quo of record inequality and exploitation.

To examine how exposure to images of militarized police affects the public’s attitude toward law enforcement, Mummolo conducted two surveys. He concluded that viewing photos of militarized police decreased respondents’ support for police funding and decreased “confidence” in the police.

One illuminating result is that Mummolo found little evidence that race influenced people’s response to images of militarized police, despite lower baseline levels of confidence in the police among African-Americans. This result suggests that workers regardless of their race correctly identify the police as their antagonists.

The reputational costs of militarization to law enforcement are “troubling,” said Mummolo, “since prior work shows that negative views of police inhibit criminal investigations and are associated with stunted civic participation.”

Contrary to what the report suggests, however, the police are not interested in greater “civic participation” in working class communities. Riot gear, percussion grenades, and assault rifles are not intended to encourage civic engagement, but to suppress it. Police terror is a means of silencing the working class and sending the message that any resistance to deteriorating working and living conditions will entail a heavy cost.

The repeal of the very mild Obama-era restrictions on police acquisition of military equipment comes as the struggles waged by teachers, UPS employees, and other workers across the country are intensifying. The fight for a living wage, for adequate health care, and for a more human existence is the real “terror” that militarized police are intended to combat.