"We are dedicating the entire resources of my office to this federal hate crime investigation and prosecution", USA attorney for western Pennsylvania Scott Brady told reporters.
Four police officers were among the wounded.
Police can be heard calling for backup and for medics, even while taking fire. Wolf lamented, "We have been saying "this one is too many" for far too long".
Bowers also reposted anti-Semitic content, including one which suggested that Trump is controlled by Jews. We believe this is the deadliest attack on the Jewish community in the history of the United States.
President Donald Trump denounced "a wicked act of mass murder", while his daughter Ivanka, a convert to Judaism, declared: "America is stronger than the acts of a depraved bigot and anti-Semite".
The departments said they were also increasing officer presence to help ease concerns from the community in response to the shooting.
The comment was posted on Gab, a Philadelphia, Pennsylvania-based social networking service created as an alternative to Twitter.
Moments before entering the synagogue on Saturday morning, the 46-year-old wrote on the social network Gab that he was "going in", stating that he couldn't "sit by and watch my people get slaughtered".
Police respond to the scene of a shooting in Pittsburgh, Pa., with the shooter now having been taken into custody.
Greenblatt released the following statement in response to the horrific and fatal anti-Semitic attack at the Tree of Life Synagogue in Pittsburgh today.
Trump told reporters later that the killings might have been prevented if there had been an armed guard in the building.
Trump - who is in IL for a campaign rally ahead of key November midterm elections - did not provide details of his trip that comes in the wake of the fatal shooting, which he earlier dubbed an "evil Anti-Semitic attack" and an "assault on humanity".
"If they had some kind of protection inside the temple maybe it could have been different", Trump reiterated his well-known view on mass shooting, which has been criticised by rights bodies and political opponents.
"He stayed to himself", said the man, who said that he lived across the street from Bowers on Fieldcrest Drive in Pittsburgh.
In the city, thousands gathered for a vigil Saturday night.
Malkin said Winnipeg's Jewish community has been inundated with support from the city's faith communities.
He said the Jewish community is often faced with bigotry.
In 2015, nine parishioners were shot and killed at a historically black church in Charleston, South Carolina, by Dylann Roof, a white supremacist who was later sentenced to nine consecutive life terms. A total of three people were killed in the shootings.