A screenshot shows alleged shooter Robert Bowers' profile on Gab, a social media platform popular among neo-Nazis, soon after the shooting Saturday.

The man accused of committing a deadly mass shooting at a Pittsburgh synagogue on Saturday was an avowed anti-Semite who police say announced his presence by shouting “All Jews must die!” before he opened fire.

Robert Bowers allegedly shot and killed at least 10 people and wounded others at the Tree of Life Congregation, which was full of people at the time. Police said he entered the building, made the anti-Semitic declaration, opened fire, and then barricaded himself inside before he was taken into custody.

Attorney General Jeff Sessions said the Department of Justice plans to file federal hate crime charges against Bowers, as well as “other criminal charges.”

“The Department of Justice will continue to support our state and local partners and we will continue to bring the full force of the law against anyone who would violate the civil rights of the American people,” Sessions said in a Saturday afternoon statement.

While a motive hasn’t been made official, it’s clear from Bowers’ online persona that he was a racist who held a deep hatred for Jewish people.

He was active on Gab, a social media platform popular among neo-Nazis, and regularly posted racist and anti-Jewish sentiments. His biography on the site said: “jews are the children of satan.”

Less than two hours before the shooting, he railed against the Hebrew Immigrant Aid Society in increasingly desperate posts, saying that he’d had enough of the “hostile invaders” and was “going in.”