Sweat covered Burnell Allen’s face as he crouched by his 5-year-old daughter Briana, who lay dying from a gunshot wound on a Central City porch.

Allen cupped her neck with his left hand. He shielded her bloody face with his right — a picture of raw pain in the moments following a fresh episode of senseless violence in a New Orleans neighborhood that knows it too well.

But in a case that highlights the violent give-and-take on some of the city’s most unforgiving streets, Burnell “Baldy” Allen, 34, now awaits trial in the murder of a 21-year-old man just days after Briana’s killing. On Monday, he sat in a federal courtroom to confront allegations that he helped run a decades-old family drug ring in the neighborhood.

A federal case that started with seven defendants has been whittled to three — Allen, Sonny “Shortbread” Allen and Gie Preston — after four others pleaded guilty to their roles in what authorities describe as a crack-dealing operation centered at the former Melpomene housing complex, known as the “Melph.”

City Councilman Jason Williams, a veteran criminal defense attorney, is one of Burnell Allen’s attorneys.

During his opening statement, Assistant U.S. Attorney Andre Lagarde promised a jury they would see reams of clandestine video footage and hear from fellow drug dealers, buyers and family members, all demonstrating that the accused men plied drugs as a family trade.

Lagarde flashed a family tree of sorts on a screen in the courtroom. At the top was Delores Allen, the family scion who lived nearby in the 1200 block of Simon Bolivar Avenue.

Though now deceased, her house until 2013 was “the epicenter of the defendants’ drug distribution activities for almost two decades,” even as the drug-dealing family members tried to hide their illicit business from her, according to court documents.

“We’re going to hear about a longtime family business. A family business that’s plagued the Central City part of New Orleans for the better part of 20 years,” Lagarde told the jury. “They’re a large, formidable family. They stick together. They watch out for each other. They watch out for police.”

Aiming to prove a conspiracy, Lagarde said the men shared at least one drug supplier, and they shared the streets.

“There’s no fighting over ‘Hey, that’s my customer. That’s my turn to sell,’ ” he said. “There’s no animosity, not even friendly competition.”

Defense attorneys for the three men didn’t dispute that each of them dealt drugs. Billy Sothern, the attorney for Preston, even conceded that “by the end of this case you will have heard evidence that establishes maybe one, maybe two of these offenses” related to his client, who faces 10 of the 14 drug, gun and conspiracy counts in the case.

But the defense attorneys said prosecutors could offer no evidence that the three men worked in tandem.

“He sold drugs, naturally. He comes from a large family, and many of them sell drugs as well,” attorney Robert Toale said of his client, Sonny Allen. “Naturally they sell drugs in the same area. That doesn’t make it a conspiracy. These are independent contractors.”

Nandi Campbell, who is representing Burnell Allen along with Williams, said prosecutors were playing off the Allen family name, which is notorious in Central City.

“Each individual had their own business,” Campbell told the jury. “It’s not enough (to say) they share suppliers. If me and my sister bought hair cream from the same place, it doesn’t mean we conspired to do something together.”

The indictment names Burnell Allen only in the two conspiracy counts, while Preston and Sonny Allen also are named in various drug and gun counts related to specific arrests in 2011 and 2013.

The two conspiracy counts — one for high-volume drug distribution, the other for guns — carry the highest potential sentences for the defendants, who are expected to face testimony from some of their co-defendants in a trial likely to run at least through Wednesday.

The jury is not expected to hear testimony about Briana Allen’s killing or any reference to the Young Melph Mafia, a group that authorities say included Lionel “Lott” Allen, who also was named in the indictment and pleaded guilty on Oct. 22 to the drug conspiracy count.

Lionel Allen was believed to be among the intended targets when members of the “110’ers,” a group centered around the former St. Thomas housing complex, came shooting on May 29, 2012, according to prosecutors. The gunfire killed Briana Allen and 33-year-old Shawanna Pierce, who caught a stray bullet while driving a rental car toward the Central Business District.

In pleading guilty, Lionel Allen admitted taking a jail phone call from Preston, telling him where to get Preston’s cocaine to give to another man so he could raise enough to post bond.

The others who pleaded guilty recently were Eugene “BeBe” Allen, Emanuel “Duke” Casame and Mark Rayfield.

Testimony began Monday with Officer Brian Pollard, who was assigned to the nearby Guste high-rise apartments when, he said, he began spotting rampant drug dealing and identifying members of the Allen family, some of whom allegedly kept wrapped packages in their mouths for easy access during drug deals.

The drug dealing occurred “morning to night. I mean constant. Every day,” Pollard testified. “It was more like a gang-type, relationship-type bond that these guys had. They were all together. They were working together. They all knew one another.”

Follow John Simerman on Twitter, @johnsimerman.