The auditorium of downtown Pittsburgh's Soldiers and Sailors Memorial Hall and Museum was packed for the 90-minute vigil, which began with music from an African-American choir.
He faces 29 criminal counts, including use of a firearm to commit murder.
Speakers said thousands more had gathered in the cold rain outside, listening in via loudspeaker.
A woman brings flowers to a memorial, Oct. 28, 2018, near the Tree of Life synagogue after a shooting there left 11 people dead in Pittsburgh, Oct. 27, 2018. "People choose to live there because of the diversity of the community".
"I felt the collective grief, and the collective vision to go forward", she said. "It will not ruin us". "We stand together with the Jewish community of Pittsburgh". We can not separate those White House claims from the gunman's social-media rage aimed at the historically Jewish refugee support organization HIAS, which plays a vital role in defending asylum seekers, saying just a few hours before his shooting rampage, "HIAS likes to bring invaders in that kill our people".
"I helped pull out the people that I could from the front", he said.
"While these attacks are nothing new in the history of our people, what is new is our ability to fight back against the anti-Semites", he said. One fortunately survived. Seven of my congregants were shot dead in my sanctuary.
'These three men, they can not be replaced, ' said Perlman, his voice breaking.
"I am numb", said Rabbi Cheryl Klein of Congregation Dor Hadash.
"You wouldn't expect it", said 30-year-old Nathan Rittri, who lives just a few houses from the Tree of Life Congregation, where the deadly shooting took place.
Klein honored Jerry Rabinowitz, who was killed in the shooting.
"Heartbroken", said Aylia Paulding, 37, her voice breaking as she summed up the grief-stricken mood.
Bowers was a long-haul trucker who worked for himself, Brady said.
"Know that we will spare no effort or resource in insuring that the defendant is held fully accountable for his unspeakable and hateful crimes", Mr. Brady said.
"There are bad hateful people everywhere but we are lucky we live in a place where police care about us and they come right away", Butler told Global News. "It is part of the fabric of Pittsburgh".
He described the neighbourhood where the shooting occurred as "the heart of the Jewish community in Pittsburgh".
"We realize that it's such a tragic time". Paying for a funeral or paying for medical costs, that is not what should be focused on.
As he prepares to conduct funerals for those who were killed, Myers said, "Maybe God has some objective for me being in the community and perhaps I'm just fulfilling what part of that goal might be".
Community leaders took time during the vigil to emphasize the need to be together in the wake of the massacre.
President Donald Trump said the outcome might have been different if the synagogue "had some kind of protection" from an armed guard, while Pennsylvania's Democratic Gov. Tom Wolf, up for re-election, noted that once again "dangerous weapons are putting our citizens in harm's way".
His account has since been suspended but screenshots have been widely circulated by SITE, a US-based extremism monitor, as well as by other media outlets.
"As Jews, anti-racist activists and residents of Ottawa, we want to send the message that hate crimes against Jews do not exist in isolation from the violent rise of white supremacy around the globe", co-organizers Genevieve Nevin and Darrah Teitel wrote.