On Dec. 4, police detain a gunman who had walked into Comet Ping Pong, a popular Northwest Washington pizza restaurant. (Sharif Silmi)

Federal prosecutors said they have offered a plea deal to a North Carolina man accused of commandeering a Washington pizza restaurant with an assault-style rifle on Dec. 4, but they did not describe the deal’s terms at a brief federal court appearance Tuesday.

Edgar Maddison Welch, 28, of Salisbury, N.C., pleaded not guilty Dec. 16 to a federal charge of interstate transportation of a firearm and ammunition and to two D.C. offenses: assault with a dangerous weapon and possessing a firearm during the commission of a crime of violence.

Welch, wearing an orange jail jumpsuit, did not speak, but Assistant Federal Public Defender Dani Jahn said during the hearing that prosecutors should continue to turn over evidence in the case. “Mr. Welch needs to understand the nature and extent of information against him to make a decision,” Jahn said.

Assistant U.S. Attorney Demian Ahn told the court that the offer was made verbally Monday and would be followed in writing Tuesday. Ahn and a spokesman for the office declined to comment afterward.

U.S. District Judge Ketanji B. Jackson set a Feb. 10 hearing, directing prosecutors by month’s end to “get as much material as possible to the defendant.”

The vast majority of federal criminal cases end in pleas, not trials, and discussions about the nature of a charge and sentencing terms should a defendant plead guilty are not unusual.

Welch faces a statutory maximum of 10 years in prison if convicted of either the federal firearms or D.C. assault charges, and a statutory maximum of 15 years in prison if convicted of the D.C. firearms count. The sentence could be far less under calculations used for federal sentencing guidelines that factor in variables such as a defendant’s criminal history, cooperation in a case and what specific offense is agreed to have occurred.

A sentencing judge is not obligated to accept a plea offer even after a defendant and prosecutors have agreed in writing to terms.

In charging documents, an FBI agent said it appeared that Welch contemplated “a violent confrontation” at the restaurant, citing text messages, call records and other information retrieved from his phone.

Police said Welch was consumed with the viral conspiracy theory known as “Pizzagate,” which falsely linked Hillary Clinton to an alleged child sex trafficking ring. The story said the ring operated in the basement of Comet Ping Pong, in upper Northwest D.C., where Clinton’s presidential campaign chairman, John Podesta, occasionally dined.

Welch prompted a panicked evacuation by customers on a Sunday afternoon, police said, when he walked into the restaurant with a .38-caliber Colt revolver and a Colt AR-15 rifle strapped across his chest.

Welch fired the assault-style weapon two or three times inside the restaurant, police said. They said he also pointed the rifle toward an employee who had emerged from a back area of the restaurant after everyone else fled.

Welch did not shoot anyone and surrendered after he found no evidence of hidden rooms or sex trafficking, police said.

D.C. Council Member Mary M. Cheh (D), a former special assistant U.S. attorney, whose Ward 3 includes the restaurant, said Tuesday that she was not surprised by the offer of a plea deal, noting that they are common and adding that she hoped a sentence would be sufficient to send a message of deterrence.

“You want to make a point that we don’t invite people in here who are vigilantes for imagined harms,” Cheh said. “You want to make a statement in that sense.”

(This file was updated to correct the title of a job formerly held by Mary M. Cheh.)

Peter Jamison contributed to this report.