PITTSBURGH — A jury is deliberating whether the man who killed 11 people at a Pittsburgh synagogue should receive the death penalty or life in prison without parole.

Robert Bowers perpetrated the deadliest antisemitic attack in U.S. history when he stormed the Tree of Life synagogue in 2018 and opened fire, killing members of three congregations who had gathered for Sabbath worship and study.

The same jury that convicted Bowers in June on 63 criminal counts began deliberating his sentence around 9:30 a.m. Tuesday morning, and returned to the courtroom soon after to look at guns that were used in the attack.

In closing arguments Monday, prosecutors said the 50-year-old truck driver was clearly motivated by religious hatred, reminding jurors that Bowers had spread antisemitic content online before the attack and has since expressed pride in the killings. They urged jurors to impose a death sentence.

Bowers’ lawyers asked jurors to spare his life, asserting that he acted out of a delusional belief that Jewish people were helping to bring about a genocide of white people. They said he has severe mental illness and endured a difficult childhood.

Bowers, who was armed with an AR-15 rifle and other weapons, also shot and wounded seven, including five responding police officers.

U.S. District Judge Robert Colville thanked the jurors for their service before sending them out to deliberate.

A short time later, as jurors huddled around the courtroom display of weapons, they asked questions of the U.S. marshal who was standing there. Bowers' attorneys objected, and the judge instructed the jury to refrain from speaking with him and to disregard everything he told them about the weapons. Colville rejected a defense request for a mistrial.