The gunman, who employees said claimed to be a Muslim angry at Israel, forced his way through the security door at the Jewish Federation in Seattle.
Naveed Afzal Haq opened fire with two semi-automatic pistols. One woman, Pam Waechter, 58, of Seattle was killed at the scene. Five more women were wounded.
Haq, 30, was held on $50 million (€73m) bail on Saturday pending formal charges of murder.
“He pointedly blamed the Jewish people for all of these problems,” Seattle Police Chief Gil Kerlikowske said.
According to a statement of probable cause, Haq told a 911 dispatcher: “These are Jews and I’m tired of getting pushed around and our people getting pushed around by the situation in the Middle East.”
Local Muslim group the Islamic Centre of the Tri-Cities offered condolences and said: “We disassociate this act from our Islamic teachings and beliefs.”
One of the women wounded in Friday’s shooting — hit in the arm as she shielded her pregnant belly — helped bring the crisis to an end by calling 911 and convincing her assailant to talk to dispatchers. That woman, Dayna Klein, 37, was hospitalised along with the four others wounded.
The 13-year-old girl taken hostage at the beginning of the melee was not shot.
Police and the FBI are labelling the shootings a hate crime.