Neo-Nazi Stephan Balliet is seen at his trial for the October 2019 attack on a synagogue in Halle, Germany. Photo: Reuters / Imago Images.

The parents of the neo-Nazi killer who murdered two people during an attempted massacre at a synagogue in Germany more than one year ago should share responsibility with their son for his crime, a lawyer representing survivors of the attack declared on Wednesday.

Speaking during gunman Stephan Balliet’s ongoing trial at the Higher Regional Court in the Saxony town of Naumberg, lawyer Assia Lewin said that his parents shouldered “a great moral responsibility” for the atrocity in the city of Halle on Oct. 9, 2019.

On that day, a heavily-armed Balliet drove to the synagogue on Humboldtstrasse in Halle just before noon, as more than 50 worshipers inside the sanctuary held religious services marking Yom Kippur, the holiest day of the Jewish year.

After failing to break through the synagogue’s locked entrance despite detonating a grenade, a frustrated Balliet shot dead a 40-year-old female passerby, named as Jana L.

When additional violent attempts to force his way inside the synagogue to attack the terrified worshipers failed, Balliet sped away in his car, driving to a small kebab restaurant where he shot dead a 20-year-old customer, Kevin S., believing him to be a Muslim.

On Wednesday, Lewin told the court that the 28-year-old Balliet had lived with his parents, becoming more and more radicalized as they maintained an attitude of “silence, looking the other way and sweeping under the carpet.”

Both Balliet’s parents and his sister have refused to testify before the court. The gunman has insisted that his family knew nothing of his plan to attack the Halle synagogue.

Lewin ended her remarks by addressing Balliet directly.

“Your deeds were neither brave nor heroic, but cowardly and despicable,” she told him. “Nobody will remember you.”

Earlier this week, the trial heard from a lawyer for the family of Kevin S., the young man murdered by Balliet at the kebab shop.

“You didn’t just shoot him dead, you agonizingly executed him,” the lawyer told Balliet. “He pleaded with you, and you shot him twice.”

Federal prosecutors are demanding a life sentence for Balliet.

The court’s verdict is expected on Dec. 21.