For Attorney General Jeff Sessions, the only way to assure a safer America and reverse rising violent crime rates is to lock up as many drug offenders as possible. Earlier this month, he directed federal prosecutors to charge suspects with the most serious offense that can be proved, a return to mandatory minimum sentencing — a key policy of the war on drugs.

“We know that drugs and crime go hand-in-hand,” Sessions said in a May 12 speech. “Drug trafficking is an inherently violent business. If you want to collect a drug debt, you can’t file a lawsuit in court. You collect it by the barrel of a gun.”

Drugs do, in fact, fuel crime. Dealers often turn to violence to carve out territories and enforce loyalty. And chronic drug users sometimes turn to crime to support their habits. But research has shown that boosting drug crime prosecutions often does not lead to a reduction in violent crime — and that in some instances, it can actually spark more of it.

“It’s pretty clear that there’s a correlation between drug arrests, crackdowns on drug markets and increase in violent crimes,” said Leo Beletsky, a professor of Law and Health Sciences at Northeastern University. “[But] the relationship is not inverse, as law enforcement would claim, but symbiotic — one causes the other, or at least they go hand-in-hand.”

Arresting and convicting a drug dealer would seem an obvious path to less overall crime. But such a move can actually destabilize a criminal ecosystem, leading to a surge in violence. When law enforcement disrupts drug markets, whether by “decapitating” — arresting a major kingpin — or taking out small-time dealers on a major scale, it can create “a power vacuum,” which gives rise to “turf wars” and “creates the conditions for violent crime,” Beletsky said.

Arresting people on the supply side of the drug trade also generally does not have the impact Sessions is seeking, he added.

A comprehensive article in the International Journal of Drug Policy from 2011 evaluated 15 studies on violence and drug crackdowns and found that increasing police activity — drug arrests, drug seizures, and police spending on drug enforcement — “paradoxically” drove up violence. One of those studies, of 67 Florida counties, found that increases in the rate of drug arrests correlated with a twofold risk of violent and property crime.

“That’s not to say that law enforcement actions are the only cause of drug-related violent crime, but they’re definitely one of the contributing factors,” Beletsky said.

Few police departments make note of motive when recording homicides and other violent crimes. Those that do show that drugs are rarely the primary motivation for killings. In New York, murders where drugs were a primary motive comprised 8.6 percent of the total murders in 2016. In Milwaukee, drug-involved homicides rose by 27 percent from 2014 to 2015, but were still only 23 percent of the total number, slightly higher than those that were alcohol-related, which accounted for 15 percent of the total number of homicides.

In making his case for a crackdown on drug offenders, Sessions has cited Federal Bureau of Investigation numbers that show a rising violent crime rate. In 2016, the national rate rose 3 percent from the year before. But that increase followed two decades of sharp decreases. The current violent crime rate is nearly half of what it was in the early 1990s.

In some American cities, like New York, the rate has continued to decline. According to an analysis published by the Brennan Center for Justice, the national uptick is attributable to a handful of cities that experienced particularly sharp surges in violence. Last year in Chicago, where police recorded more than 4,300 shootings, the violent crime rate increased 17.7 percent. There were 762 homicides, the highest number in nearly two decades.

Richard Aborn, a former prosecutor with the Manhattan district attorney’s office and now the president of the Citizens Crime Commission of New York City, credits falling crime rates in his city to “precision policing.”

“[An] irrefutable lesson we’ve learned from the fight against crime is that society is made much safer when police use scalpels, not bludgeons,” he said. “Sessions is talking about bringing bludgeons back.”

Peter Moskos, a former Baltimore police officer who now teaches at John Jay College of Criminal Justice, added that one reason that New York doesn’t have the same problem with violent crime as Chicago is because of a change in the drug market: dealers started delivering drugs to their customers instead of “slinging on the corner.” The result, according to Moskos: dealers “stopped shooting each other.”

“There’s no indication that drug use went down,” he said. “Other cities, like Baltimore and Chicago, still have active street markets.”

Sessions laid out a three-pronged approach for bringing down crime: criminal enforcement, treatment, and prevention. Both Beletsky and Moskos agreed the biggest failure of the decades spent devoted to the war on drugs has been overlooking the latter two. They fear that Session’s clear preference for incarcerating people over helping them surmount addiction and its fallout will do nothing to slow either the pace of shootings in Chicago, or of an opioid crisis that is out of control in rural America.

Moskos recalled a recent photo that went viral on the Internet of a little boy in East Liverpool, Ohio, sitting in the backseat of a car while two adults overdosed in the front. Moskos was struck by the local police chief’s recognition after the incident that law enforcement is ill equipped to address the issues that created the situation depicted in that photo.

“We don’t have any resources, and we don’t have a place. Even if somebody comes down here to the station, knocks on the door and asks for help, where do we send them?” East Liverpool police chief John Lane said on NPR at the time. “We have nothing here in our county.”