Tree of Life Synagogue in Pittsburgh
Tree of Life Synagogue in PittsburghReuters

A lawyer for Robert Bowers, who carried out the shooting attack at the Tree of Life Synagogue in Pittsburgh in 2018, claimed on Monday that the gunman had psychotic, delusional and paranoid symptoms that made him unable to understand the world or make appropriate decisions, The Associated Press reported.

Bowers was found guilty earlier this month on all 63 federal charges brought against him, some of which are punishable by death.

Bowers has had a psychotic condition since childhood, as well as serious brain defects and a history of suicide attempts, defense lawyer Michael Burt said on the opening day of the penalty phase of Bowers' federal trial.

The defense argues that Bowers was unable to form the requisite level of intent to allow the jury to impose a death sentence. Medical tests found Bowers’ brain to be “structurally deficient,” with symptoms of epilepsy and schizophrenia, Burt said.

Prosecutor Troy Rivetti, in his opening statement Monday, said the government was prepared to rebut any mental health defense.

Bowers clearly intended to kill everyone he could find in the synagogue on October 27, 2018, Rivetti said, according to AP. He called the magnitude of Bowers' crimes staggering.

“He came to kill,” Rivetti said. “The defendant entered the Tree of Life Synagogue, a sacred place to gather and pray, and he murdered 11 innocent worshippers.”

Bowers was initially indicted on 44 counts. In January of 2019, a federal grand jury added 19 charges to the 44 counts previously levied against Bowers. He had pleaded not guilty to all 63 counts, including hate crimes.

His defense team had previously argued that the defendant suffers from schizophrenia. They offered a guilty plea in exchange for life in prison, which was rejected by the prosecution.

If jurors decide Bowers deserves to die, it would be the first federal death sentence imposed during Biden's presidency.