In a case that has become a flash point in an increasingly bitter battle between U.S. Attorney William M. McSwain and Philadelphia District Attorney Larry Krasner, federal prosecutors filed charges Thursday against a West Philadelphia AK-47 gunman who received what critics of Krasner considered a lenient plea deal.

McSwain, the city’s top federal law enforcement officer, announced a federal indictment against Jovaun Patterson, 29, at a news conference. Patterson shot and nearly killed a store owner with the assault-style rifle during an attempted robbery May 5, and under the plea deal was sentenced to 3½ to 10 years in state prison.

Saying Krasner’s office did not give victim Mike Poeng justice, McSwain unleashed criticisms of Krasner’s policies, stating that “when the office consistently undercharges violent-crime cases, when it offers sweetheart deals to violent defendants, when its overall stated priority is decarceration, when it leads the charge for lenient bail conditions … when the district attorney refers to himself as a ‘public defender with power’ — violent criminals take notice of all of that. And they become emboldened. They think they can literally get away with murder.”

McSwain, flanked by Assistant U.S. Attorney Salvatore Astolfi and agents of the Bureau of Alcohol, Tobacco, Firearms and Explosives, contended that Krasner’s policies have a “very, very strong correlation” with last year’s rise in homicides in the city.

A chart on an easel showed Philadelphia homicides from 2013 to 2018, a year when 351 homicides were recorded in the city, more than in any other year since 2007 and 11 percent higher than in 2017.

About two hours later, Krasner responded to McSwain in a hastily scheduled news conference of his own. The district attorney had not been consulted about the federal indictment, but said he nonetheless welcomed it. But he said it was unfair to blame him or his office for last year’s increase in homicides.

“We are in the middle of an opioid epidemic,” Krasner said, criticizing McSwain’s comments, adding: “It is highly inappropriate to frighten the people who live in Philadelphia.”

Police Commissioner Richard Ross and Krasner both said in December that drug-related homicides contributed to the city’s increase. As of Dec. 30, police statistics showed that drugs were listed as the primary factor in 130 homicides during the year, nearly double the 66 drug-related killings in 2017.

Krasner said those statistics are based on “evidence and science," and contended that McSwain’s comments originated from “political” motives.

Patterson’s attorney, S. Philip Steinberg, said in a text message after the federal announcement that he looked forward to advocating on his client’s behalf.

Patterson pleaded guilty Nov. 15 in Common Pleas Court to aggravated assault and related offenses in the shooting of Poeng, then 50, during an attempted robbery outside Poeng’s beer deli at 54th and Spruce Streets.

The plea deal stunned Poeng, who was not notified of it or the sentencing hearing, in violation of the Pennsylvania Crime Victims Act. It also sparked criticism after the agreement was first reported by the Inquirer.

Poeng, who was shot in the groin and can no longer walk on his own, attended McSwain’s news conference in a wheelchair, accompanied by family members, none of whom spoke during the news conference. Tom Malone, an attorney for Poeng, told reporters afterward: “They’re extremely happy that the U.S. Attorney’s Office has taken up the mantle and has decided to pursue this case.”

Poeng told the Inquirer, “I’m happy with the outcome.”

The federal indictment charges Patterson with a Hobbs Act robbery, which targets criminals who rob or attempt to rob a business engaged in interstate commerce, and with carrying and using a firearm in a crime of violence. If convicted under the federal firearm statute, Patterson would face a mandatory minimum sentence of 10 years, consecutive to any other sentence he is to serve.

Patterson’s case is the first during Krasner’s tenure in which federal prosecutors have filed charges after a defendant was convicted and sentenced in the city court system.

Former federal prosecutors interviewed could not cite a case in which the U.S. Attorney’s Office in Philadelphia filed charges after a defendant had been prosecuted and sentenced in the city system for the same offense.

Linda Dale Hoffa, a Center City criminal defense attorney who previously worked for the U.S. Attorney’s Office in Philadelphia — including as chief of the criminal division — called the scenario “unusual.”

“I do not remember a time when a matter was prosecuted at the federal level after sentence was imposed at the state level,” Hoffa said.

Federal prosecutors were able to charge Patterson, who is currently at the State Correctional Institution in Coal Township in central Pennsylvania, after approval from the Justice Department under its “Petite Policy,” which allows a federal prosecution following a state prosecution on the same incident if the matter involves a “substantial federal interest” and the state prosecution was deemed “unvindicated” or inadequate.

Under the “dual-sovereignty doctrine,” the federal and state governments are deemed separate “sovereigns” and each may prosecute a person for the same act without violating the Constitution’s protection against double jeopardy if the person’s conduct violated both jurisdictions’ laws.

When the Inquirer first reported about the district attorney’s plea deal, Krasner’s spokesperson, Ben Waxman, called it “wholly appropriate.” After criticism emerged, Krasner in a Dec. 7 motion asked Common Pleas Court Judge Rayford Means to vacate the deal and sentence. The District Attorney’s Office blamed the assistant district attorney who handled the case for offering the deal without supervisory approval.

In a Dec. 18 WHYY-FM Radio Times interview, Krasner said that although his office did not notify Poeng of the deal, it had “extensive contact with the victim — even in hospital, there was extensive contact.”

Poeng says that’s not true. He has said that a district attorney’s victim-services coordinator visited him just once, when he was at Magee Rehab.

Krasner also implied in the radio interview that Means could vacate Patterson’s sentence, which he called “insufficient.” He didn’t mention that Means, at an impromptu Dec. 12 status hearing, acknowledged there was no legal basis for him to reconsider a negotiated sentence.

Means had scheduled a Feb. 11 hearing for Poeng to give a victim-impact statement, but Poeng was unable to go because of recent surgery. The hearing was postponed to April.

Not able to work, Poeng was forced to sell his store.

McSwain, asked at his news conference if he expects to federally charge more city cases after they have been sentenced, said, “My hope is, no. My hope is the District Attorney’s Office will do what it’s supposed to do.”