WASHINGTON (Reuters) - Federal authorities on Tuesday added 19 hate-crime and firearms charges to their case against a Pennsylvania man accused of massacring 11 people at a Pittsburgh synagogue last October in the deadliest anti-Semitic attack in U.S. history.

Police vehicles are deployed near the vicinity of the home of Pittsburgh synagogue shooting suspect Robert Bowers' home in Baldwin borough, suburb of Pittsburgh, Pennsylvania, U.S., October 27, 2018. REUTERS/John Altdorfer

The suspect, Robert Bowers, 46, could face the death penalty if convicted on any of 22 capital-eligible offenses contained in the full 63-count superseding indictment returned by a federal grand jury in Pittsburgh.

A onetime truck driver who frequently posted anti-Semitic slurs online, Bowers is accused of storming the Tree of Life synagogue during Saturday services on Oct. 27 and yelling “All Jews must die.”

The new charges against Bowers, who has pleaded not guilty to 44 earlier charges, include obstructing free exercise of religious beliefs that led to death and injury, committing hate crimes resulting in death and discharging a firearm.

In addition to the mostly elderly congregants who died in the shooting, authorities said two were wounded, along with five police officers, before Bowers surrendered and was taken into custody after he was wounded in a shootout with police.

Federal authorities said Bowers entered the synagogue in the city’s Squirrel Hill neighborhood, a heavily Jewish area, armed with multiple firearms, including three Glock .357 handguns and a Colt AR-15 rifle.

Bowers, a Pittsburgh resident, had made many anti-Semitic posts online, including one early on the day of the attack that said, “I can’t sit by and watch my people get slaughtered. Screw your optics, I’m going in.”

In another, he slammed U.S. President Donald Trump for doing nothing to stop an “infestation” of the United States by Jews.

At a Nov. 1 court appearance, Bowers pleaded not guilty to the first 44 counts filed against him after entering the courtroom wearing a red jumpsuit and a bandage on his left arm. He also requested a jury trial.

The attack followed a spate of politically motivated pipe-bomb mailings to prominent Democrats. It also fueled a debate over Trump’s inflammatory political rhetoric and his self-identification as a “nationalist,” which critics say has fomented a surge in right-wing extremism and may have even helped provoke the bloodshed in Pittsburgh.

The Trump administration has rejected the notion that the president has encouraged white nationalists and neo-Nazis who have embraced him, insisting that Trump is trying to unify America even as he disparages the media as an “enemy of the people.”