PITTSBURGH — The man charged in the Pittsburgh synagogue massacre pleaded not guilty to hate crimes and dozens of other counts Monday, but his new lawyer – a prominent death penalty litigator who represented one of the Boston Marathon bombers – signaled he might be open to a plea deal.

Robert Bowers, a truck driver who authorities say gunned down 11 people at Tree of Life Synagogue, appeared in federal court with attorney Judy Clarke, who expressed hope the case will be resolved without a trial.

Clarke is known for negotiating plea deals that helped some of the nation’s most infamous killers avoid death row, including Unabomber Ted Kaczynski, Atlanta Olympics bomber Eric Rudolph and Arizona shooter Jared Lee Loughner, who killed six people and injured 13 others, including U.S. Rep. Gabrielle Giffords.

A jury sentenced Boston Marathon bomber Dzhokhar Tsarnaev, whom Clarke represented, to death.

Prosecutors in Pittsburgh have previously indicated their intent to seek the death penalty against Bowers, but a final decision rests with the U.S. attorney general.

Asked if the government would consider a plea deal that spares Bowers a potential death sentence, U.S. Attorney Scott W. Brady said in a statement Monday: “The defendant is charged with crimes that carry the maximum possible penalty of death. We are committed to seeking justice for the victims and their families in this case.”

Assistant U.S. Attorney Troy Rivetti said in court that a trial could last about three weeks, not including any potential penalty phase.

Bowers, who was shackled, said little, giving yes or no answers.

A grand jury on Jan. 29 added 19 counts to the 44 Bowers was already facing.

The additional charges include hate crimes violations, obstruction of religious belief and the use of a firearm during crimes of violence.

Bowers, 46, of Baldwin, Pennsylvania, is accused of targeting worshippers from three Jewish congregations when he attacked Saturday, Oct. 27, during Sabbath services.

Seven people were wounded, including five police officers.

Donna Coufal, a member of the Dor Hadash congregation that occupies space at Tree of Life, said she attended Monday’s arraignment “to bear witness.”

“It’s been a painful time, but we remain strong as a community,” Coufal said.