D.C. police and federal agents will work closely together this year in a crackdown on convicted felons illegally carrying guns in the city, a law enforcement strategy prompted by a steep increase in homicides in 2018, officials said Wednesday.

The new approach — in which U.S. authorities will play a greater role in investigating local gun-possession offenses in the District — will involve prosecuting many “felon-in-possession” defendants in federal court rather than D.C. Superior Court, officials said. That could result in longer prison terms in some cases.

Mayor Muriel E. Bowser (D) and U.S. Attorney Jessie K. Liu of the District, appearing at a news briefing Wednesday, praised the plan, which Bowser attributed to Liu.

“Today the U.S. attorney briefed me on a new strategy her office has launched that will take more illegal gun cases [to federal court], specifically cases where a previously convicted felon is . . . arrested and charged with illegally possessing a gun,” Bowser said.

“I support the U.S. attorney’s strategy and believe it will send a clear message that violence will not be tolerated in the District,” the mayor added.

Earlier this week, after officials outlined the strategy to The Washington Post, speaking on the condition of anonymity ahead of Wednesday’s announcement, the head of the American Civil Liberties Union in the District criticized it as “reactionary,” suggesting it would aggravate the problem of mass incarceration.

As Bowser spoke Wednesday, she seemed aware of the criticism, which had been echoed by others. She began her remarks by pointing out that last week, she and D.C. Attorney General Karl A. Racine announced a $6 million investment in the District’s workforce development and violence prevention efforts.

“We know that guns have a devastating effect on families, neighborhoods and our entire city,” she said. “Reducing this violence requires an approach that’s not just specific to law enforcement, but also focused on human services and the community. And together we know that we will address every aspect of the problem we are experiencing.”

Liu said the FBI, the U.S. Marshals Service, the Bureau of Alcohol, Tobacco, Firearms and Explosives and other federal agencies “will be working closely” with D.C. police from start to finish on felon-in-possession cases.

She has previously described the shift and refocusing of federal law enforcement resources as a “homegrown” option that emerged in talks with D.C. authorities over how to combat escalating violence.

“This strategy will enable us to leverage local and federal law enforcement resources throughout the District from the ground level up,” she said Wednesday, “giving us an opportunity from the very start of a case to try to find out where these firearms are coming from, how they’re being used and what we can do to prevent further violence.”

In Superior Court, a defendant with a felony record who is convicted of illegal gun possession can be sentenced to up to 15 years, depending on the circumstances of the case. But many receive sentences in the one-to-three-year range, according to sentencing reports for D.C. Superior Court cases and attorneys.

Under the federal law dealing with felons in possession, defendants convicted in U.S. District Court are exposed to longer sentences, depending on the circumstances of their cases.

In 2018, there were 350 such gun cases filed in the District, but just 25 percent of them were charged as federal crimes. The city also recorded 160 homicides last year, an increase of about 40 percent over the 2017 total.

Asked whether the shift of cases to the federal court was meant to achieve longer prison terms, Bowser and Liu played down that aspect of the strategy. “Those cases will be prosecuted in federal court because we’re going to be working more closely with our federal partners, and that is typically where they bring their cases,” Liu said.

Bowser noted that case dockets are less crowded in federal court than in Superior Court.

“I think what we should be focused on is how quickly these cases can be brought, “ she said. “That protects the guilty and the not guilty. So the guilty are going to get their justice, and the not guilty are going to get a swift trial.”