PITTSBURGH — The trial of the man charged in the deadliest antisemitic attack in U.S. history opened Tuesday with his own lawyer acknowledging that he planned and carried out the 2018 massacre at a Pittsburgh synagogue and made hateful statements about Jewish people.

Robert Bowers went to Tree of Life synagogue and “shot every person he saw,” defense attorney Judy Clarke acknowledged in her opening statement.

Bowers, 50, could face the death penalty if he's convicted of some of the 63 counts he faces in the Oct. 27, 2018, attack, which claimed the lives of 11 worshippers from three congregations who shared the building. Charges include 11 counts each of obstruction of free exercise of religion resulting in death and hate crimes resulting in death.

In the long run-up to the trial, Bowers' lawyers did little to cast doubt on whether he was the gunman and instead focused on trying to save his life. Bowers, a truck driver from the Pittsburgh suburb of Baldwin, had offered to plead guilty in return for a life sentence, but federal prosecutors turned him down.

In her opening statement, Clarke questioned whether Bowers was acting out of hatred or an irrational belief that he needed to kill Jews to save others from the genocide he claimed they were enabling by helping immigrants come to the U.S.

"He had what to us is this unthinkable, nonsensical, irrational thought that by killing Jews he would attain his goal," Clarke said, adding: "There is no making sense of this senseless act. Mr. Bowers caused extraordinary harm to many, many people."

In their opening statement to the jury, prosecutors described how Bowers barged into the synagogue and shot every worshipper he could find.

"The depths of the defendant's malice and hate can only be proven in the broken bodies" of the victims and "his hateful words," Assistant U.S. Attorney Soo C. Song said.

Some of the survivors dabbed tears during Song's presentation, while Bowers, seated at the defense table, showed no reaction.

Twelve jurors and six alternates — chosen Thursday from among more than 200 candidates — are hearing the case. They include 11 women and seven men.

Members of the three congregations arrived at the courthouse in a school bus and entered together. The atmosphere in the large, wood-paneled courtroom was grim and somber as the gallery filled with media, survivors and family members,

Prosecutors have said Bowers made antisemitic comments at the scene of the attack and online.

As an indication that the guilt-or-innocence phase of the trial seemed almost a foregone conclusion, Bowers' lawyers spent little time during jury selection asking how potential jurors would come to a verdict.

Instead, they focused on the penalty phase and how jurors would decide whether to impose the death penalty in a case of a man charged with hate-motivated killings in a house of worship. The defense probed whether potential jurors could consider factors such as mental illness or a difficult childhood. Bowers' attorneys recently said he has schizophrenia and brain impairments.

The families of those killed are divided over whether the government should pursue the death penalty, but most have voiced support for it.

The trial is taking place in the downtown Pittsburgh courthouse of the U.S. District Court for Western Pennsylvania, presided over by Judge Robert Colville, an appointee of former President Donald Trump.

Prosecutors have said Bowers made incriminating statements to investigators and left an online trail of antisemitic statements that they say shows the attack was motivated by religious hatred. Police shot Bowers three times before he surrendered.

After opening statements, prosecutors began presenting their case by playing an initial 911 call from Bernice Simon, who reported "we're being attacked!" at the synagogue and that her husband, Sylvan Simon, had been shot.

Shannon Basa-Sabol, the dispatcher who took that call, testified that she advised Bernice Simon to find the wound and stanch the bleeding. Then the dispatcher heard additional gunfire and screaming as Bernice, too, was shot. Neither of the Simons survived.

"Bernice, are you still with me?" Basa-Sabol asked in the recording, There was no answer.

Bowers also injured seven people, including five police officers who responded to the scene, investigators said.

In a filing earlier this year, prosecutors said Bowers "harbored deep, murderous animosity towards all Jewish people." They said he also expressed hatred for HIAS, founded as the Hebrew Immigrant Aid Society, a nonprofit humanitarian group that helps refugees and asylum seekers.

Prosecutors wrote in a court filing that Bowers had nearly 400 followers on his Gab social media account "to whom he promoted his antisemitic views and calls to violence against Jews."

The three congregations have spoken out against antisemitism and other forms of bigotry since the attack. The Tree of Life congregation also is working with partners on plans to overhaul its current structure, which still stands but has been closed since the shootings, by creating a complex that would house a sanctuary, museum, memorial and center for fighting antisemitism.

The death penalty trial is proceeding three years after now-President Joe Biden said during his 2020 campaign that he would work to end capital punishment at the federal level and in states that still use it. His attorney general, Merrick Garland, has temporarily paused executions to review policies and procedures, but federal prosecutors continue to vigorously work to uphold death sentences that have been issued and, in some cases, to pursue new death sentences at trial.