This courtroom sketch depicts Robert Bowers, who was wounded in a gun battle with police, as he appeared in a wheelchair in federal court on Monday. (Dave Klug/ AP)

PITTSBURGH — The man accused of gunning down 11 congregants in a synagogue appeared in court Thursday morning and pleaded not guilty to the dozens of charges he faces.

Robert Bowers, 46, has been charged with walking into Tree of Life synagogue here on Saturday morning and opening fire while repeatedly expressing his desire to “kill Jews.” Authorities said Bowers killed 11 people inside the synagogue, critically injured two other congregants and also wounded four of the law enforcement officers who exchanged fire with him.

During a brief court appearance Thursday, Bowers, wearing a red jumpsuit, heard the charges against him, some of which could ultimately result in the death penalty if he is convicted.

Bowers appeared with Michael J. Novara, his public defender, before Magistrate Judge Robert C. Mitchell. Unlike a court appearance in front of Mitchell on Monday, when Bowers was seated in a wheelchair, he walked into this hearing, his hands shackled and a chain hanging off his waist. Bowers was hospitalized for two days after the shooting after being shot multiple times, but he has since been released and is in federal custody.

During the hearing, Bowers sat slouched over the table, wearing a fixed somber expression while prosecutors listed the charges against him and reminded him that he could receive a death sentence if convicted. He also requested a jury trial. Novara, his public defender, had no comment Thursday.

In court documents, officials estimated Bowers’s eventual trial could last between three and four weeks. A status conference in the case was scheduled for Dec. 11.

Among the charges Bowers faces are 11 counts of obstruction of free exercise of religious beliefs resulting in death. The Justice Department has said federal prosecutors in Pittsburgh have begun the process of seeking a possible death sentence in the case; such decisions are made by the attorney general after a review by federal lawyers who specialize in capital cases. When the charges against Bowers were announced, Attorney General Jeff Sessions decried the “incomprehensibly evil and utterly repugnant” allegations laid out in the indictment.

The attack on the synagogue was the deadliest on Jews in American history. Among the victims were two brothers who had attended the services each week since their childhood, a doctor who led its Torah studies and a man who sat in the back and handed prayer books to people who arrived late.

Mourners have spent this week attending funeral after funeral for the massacre’s victims and remembering the lives lost in the synagogue. Although no decision has been made on a possible death sentence, one of the factors federal prosecutors can cite in seeking such a penalty is whether victims are particularly old or young; six of the 11 victims at the synagogue were at least 70 or older.

Local prosecutors also have filed charges against Bowers, but Allegheny County District Attorney Stephen A. Zappala Jr. said this week that he will put that prosecution on hold while the federal case proceeds. Zappala has signaled that he is likely to pursue a death sentence for Bowers.

Investigators are continuing to scour Bowers’s life looking for what could explain his turn toward extremist violence. Although his online presence was rife with vitriolic hatred of Jewish people and other bigotry, in real life he was a forgettable presence who gave no indications of the carnage officials say he unleashed.

Bowers’s mother, Barbara Bolt, is distraught about the shooting, said the Rev. Mark Schollaert, pastor of First Baptist Monongahela Church, where Bolt is a parishioner. Schollaert said Bolt had asked him to speak on her behalf.

“She doesn’t condone at all what her son has done,” Schollaert said. “She’s praying for the families of the victims and their friends.”

Berman reported from Washington. Kayla Epstein in Pittsburgh contributed to this report.

Further reading:

The stories of the Pittsburgh victims

Funerals are underway for the victims of the attack