PITTSBURGH — The anti-Semitic truck driver accused of gunning down 11 people at a Pittsburgh synagogue pleaded not guilty Thursday to federal charges that could put him on death row, as funerals for the victims continued for a third day.

Robert Bowers, 46, was arraigned one day after a grand jury issued a 44-count indictment charging him with murder, hate crimes, obstructing the practice of religion and other crimes. It was his second brief appearance in a federal courtroom since the weekend massacre at Tree of Life synagogue in Pittsburgh’s Squirrel Hill neighborhood.

“Yes!” Bowers said in a loud voice when asked if he understood the charges.

Authorities say Bowers raged against Jews during and after the deadliest anti-Semitic attack in American history. He remains jailed without bail.

Bowers, who was shot and wounded during a gunbattle that injured four police officers, walked into court under his own power, his left arm heavily bandaged. He was in a wheelchair at his first court appearance Monday.

Bowers frowned as the charges were read but did not appear to have a reaction as a federal prosecutor announced he could face a death sentence. He told a prosecutor he had read the indictment.

Bowers had been set for a preliminary hearing on the evidence, but federal prosecutors instead took the case to a grand jury.

The panel issued the indictment as funerals continued for the victims, including a husband and wife married at Tree of Life 62 years ago.

Marc Simon, the son of Bernice and Sylvan Simon, recalled his parents as a “beacon of light” whose example can help “eliminate the hate that led to their untimely deaths.”

Hundreds of mourners turned out for the funeral, according to the Pittsburgh Post-Gazette.

Family members recalled the Simons as warm and welcoming, and dedicated to their faith and one another.

Their daughter, Michelle Simon Weis, said she enjoyed going with her mother to Costco, where Bernice, 84, made sure to try the food samples. Weis said she dreamed her father, 86, could now drive a sports car as fast as he wanted without “Mom telling him to slow down.”

The day’s other funeral was being held for Dr. Richard Gottfried, a dentist who worked part time at a clinic treating refugees and immigrants. The oldest victim, 97-year-old Rose Mallinger, will be honored at the last service Friday. Her daughter was injured in the attack.

Tree of Life remained a crime scene. Rabbis and other volunteers have been cleaning the temple to remove all bodily traces from the 11 victims, following Jewish law regarding death and burial.

Meanwhile, 911 operators who were on duty Saturday morning described how they could hear gunshots and screaming as the rampage unfolded.

Bruce Carlton, who took the initial call from Tree of Life Rabbi Jeffrey Myers, said he wanted to keep Myers on the phone without revealing his position to the gunman.

“I didn’t want him to speak. I tried not to speak. I didn’t want the gunman to hear him. I didn’t want the gunman to hear me,” Carlton told KDKA-TV. He said the call “seemed so surreal, like it wasn’t happening.”

After learning that Myers had made it unscathed, Carlton said he was left shaking.