Federal prosecutors will seek the death penalty for Robert Bowers, who is accused of killing 11 Jewish worshippers at the Tree of Life*Or L’Simcha Synagogue in Pittsburgh on Oct. 27, 2018, according to a filing on Monday.

In the filing in the U.S. District Court of Western Pennsylvania, the Department of Justice listed numerous factors behind its decision, including that Bowers “expressed hatred and contempt toward members of the Jewish faith and his animus toward members of the Jewish faith played a role in the killings.”

Bowers has pleaded not guilty to more than 50 criminal charges in the case, including federal hate-crime charges.

“Bowers targeted men and women participating in Jewish religious worship at the Tree of Life Synagogue, located in the Squirrel Hill neighborhood of Pittsburgh, Pennsylvania, which is home to one of the largest and oldest urban Jewish populations in the United States, in order to maximize the devastation, amplify the harm of his crimes and instill fear within the local, national, and international Jewish communities,” stated prosecutors in the filing.

The mass shooting was the most lethal anti-Semitic attack in U.S. Jewish history.