Mayor Muriel E. Bowser (D) and D.C. Police Chief Peter Newsham discuss gun and drug seizures at a news conference Wednesday at police headquarters. A unit targeting large-scale drug distributors has already seized more guns from District streets than in all of 2016.

A D.C. police squad formed two years ago to target drug distributors seized more guns in the first four months of this year than it did in all of 2016, which authorities say has helped achieve a sharp reduction in violent crime.

Mayor Muriel E. Bowser (D) and Police Chief Peter Newsham singled out the Narcotics Enforcement Unit on Wednesday ahead of the summer months, when crime has traditionally increased in the city.

Homicides have remained steady in the District this year compared to last — tied at 40 — but robberies, sex assaults and assaults with weapons are all down this year, leading to a 25 percent decrease in violent crime overall. The drug unit recovered 49 firearms through the beginning of May; it confiscated 42 in all of 2016. In all, the department seized 1,870 guns last year.

“The goal of this unit was to focus on the illegal drugs in our community, and not on the users,” Newsham said during a news conference at police headquarters. The chief described a “laser focus on drug distributors who were contributing to the violence in our city.”

Newsham said the narcotics unit seized more than $200,000 in illegal cocaine, heroin, PCP, synthetic opioids and methamphetamine in 2016. This year, the detectives have taken $90,000 in illegal drugs off the streets. He said detectives are concentrating efforts in areas where there is violence and then looking for drugs being sold.

The drug squad was formed in 2015 in part because authorities said public corners were no longer being used to sell most drugs, and that required easing away from arrests that swept people off the streets. The shift also addressed complaints from residents who accused plainclothes detectives of jumping out of cars and indiscriminately targeting people standing around.

The D.C. police department, as is law enforcement in other cities, is moving away from targeting drug addicts for arrests. “The cause of drug use is a public-health issue called addiction,” Newsham said. “The cause of drug sales is a condition known as greed. To the extent that this greed contributes to violence in our city, the police are focused on addressing it.”

Bowser has asked for nearly $1 million in the 2018 police budget to work with the D.C. Department of Behavioral Health so that officers can divert drug addicts into programs instead of a jail cells. She said she wants to “provide public safety officials with the tools they need to crack down on drug suppliers” while also helping addicts “fight and recover from drug use and addiction.”

On Tuesday, Bowser met with Maryland Gov. Larry Hogan (R) and Virginia Gov. Terry McAuliffe (D) and vowed to work with them to prevent misuse of prescription drugs, which experts say is at the root of a surge in opioid overdoses across the country.

The police chief, a veteran of the D.C. force who was confirmed by the D.C. Council this month, also said he will continue what is called a Summer Crime Prevention Initiative, launched in 2010 and designed to throw the resources of police and other agencies into six neighborhoods hit hardest by crime. This year, five will be east of the Anacostia River, and one will be in Northeast Washington. The effort occurs when school is out.

On Tuesday evening, police said, three juveniles were shot on a basketball court on a playground in Edgewood in Northeast Washington. The shooting occurred about 6:15 p.m. and came from a gunman in a gray sedan in the 300 block of Franklin Street NE.

The injuries were described as not serious and there was no known motive, but police described the shooting as typical of a summer evening. While homicides this year are even with 2016, the numbers are down from 2015, when a spike in summer shootings raised concerns.

“The good news is that you don’t hear about it as often as you used to,” Newsham said of incidents like the basketball court shootings. “The bad news is that it still happens in our city.”