On Monday, suspected gunman Robert Bowers was brought into federal court in a wheelchair for his first appearance. Wearing a blue shirt and handcuffs -- which US marshals removed so he could sign paperwork -- he spoke only to answer questions from the judge.
"It's hard to understand how significant these losses are to our community unless you understand the significance and intimacy of Squirrel Hill," said Tree of Life congregant Jesse Rabner said.
"The community is knit so tight that one life affects thousands. It's a norm to be Jewish in Squirrel Hill, and it's a loving and peaceful community."
Rabbi Hazzan Jeffrey Myers with Tree of Life said his synagogue will rebuild and "be back stronger and better than ever."
"You can cut of some branches from our tree, but Tree of Life has been in Pittsburgh for 154 years. We're not going anywhere," the rabbi told CNN's "New Day" on Monday. "I will not let hate close down my building."
Attorney General Jeff Sessions must ultimately give the OK to pursue the death penalty for the alleged gunman, Robert Bowers, the Justice Department said. The attack was the deadliest against Jews in US history.
"At this point in our investigation, we're treating it as a hate crime," Scott Brady, the US attorney for the Western District of Pennsylvania, said Sunday.
When asked if the shooting could be considered an instance of domestic terrorism, Brady said there would need to be evidence the suspect tried to propagate a particular ideology through violence.
In an address on Monday in Boston, Sessions labeled the assault a "murderous rampage" and said, "This was not just an attack on the Jewish faith. It was attack on all people of faith, and it was an attack on America's values of protecting those of faith. It cannot, it will not, be tolerated."
Sessions said authorities will conduct the case "with vigor and integrity."
"He'll be subjected to the death penalty perhaps," the attorney general said of the suspect.
Bowers is expected back in court for a preliminary hearing Thursday morning. While two public defenders appeared with him in court Monday, the lawyer or lawyers who will handle his case going forward have yet to be appointed. He is being without bond.
Brady will present the case to a federal grand jury within 30 days, he said.
"They're committing genocide to my people," Bowers told police during the shooting, according to an FBI affidavit. "I just want to kill Jews."
The suspect was taken into custody after a shootout with police and was treated at Allegheny General Hospital in Pittsburgh. Bowers was released at 9:45 a.m. Monday, a spokeswoman for Allegheny Health Network said.
He faces at least 29 federal charges, including 11 counts of obstruction of exercise of religious beliefs resulting in death, plus 11 counts of using a firearm to commit murder. A conviction on any could be punishable by death, US Attorney Brady said.
In the shootout with police, Bowers also faces four counts of obstruction of exercise of religious beliefs resulting in bodily injury to a public safety officer and three counts of use and discharge of a firearm during and in relation to a crime of violence.
He has also been charged with 11 state offenses, including attempted homicide and aggravated assault.
Federal prosecutors filed a "request for detention" for Bowers on Monday morning, court documents show.
The documents say Bowers is a flight risk and a danger to the community, and there's the serious risk that he will "obstruct or attempt to obstruct justice, or threaten, injure, intimidate or attempt to threaten, injure, or intimidate, a prospective witness or juror."
Residents mourn victims in interfaith service
The massacre was part of a week of traumatic events with common roots in hate. President Donald Trump ordered flags flown at half-staff in honor of the victims.
All corners of the Pittsburgh region mourned, including the city's sports teams and athletes.
The Pittsburgh Steelers held a moment of silence on Sunday before their game against the Cleveland Browns. After the game, which the Steelers won, coach Mike Tomlin mourned the victims.
"Let me start by representing our organization and saying our hearts go out to the victims of yesterday's shooting, the Squirrel Hill community and the community of Pittsburgh at large," said Tomlin, a member of the Squirrel Hill community.
Visiting dignitaries joined the community's leaders, politicians and residents at the University of Pittsburgh for an interfaith service. They pledged to support the community and fight hate speech.
"We will drive anti-Semitism and the hate of any people back to the basement, on their computer, and away from the open discussions and dialogues around this city, around this state and around this country," Pittsburgh Mayor Bill Peduto said.
On Monday, Pittsburgh public schools were to hold a moment of silence as students headed back to class.
"Please know that to support our students and staff, in the schools most affected by this tragedy, we will have both student and employee assistance available. As always, our School Police works closely with the City of Pittsburgh Police to ensure an appropriate presence throughout the District," said a message on the public schools website.
A trail of hate leads to suspect
Sunday's vigil, the second since the Saturday morning shooting, came as a more detailed picture began to emerge of the suspect.
Investigators searched Bowers' home with a robot Saturday and searched his vehicle Sunday, the FBI said. Agents are also looking for surveillance footage from the area that could provide clues.
For weeks before the shooting, Bowers targeted Jews in frequent posts on Gab, a social media platform that bills itself as "the free speech social network." He used anti-Semitic slurs, complained that President Donald Trump was surrounded by too many Jewish people and blamed Jews for helping migrant caravans in Central America.
He also posted pictures of his handgun collection. Bowers has 21 guns registered to his name, said US Rep. Mike Doyle, a Democrat whose district includes Squirrel Hill.
Investigators have been in contact with police in Dormont, a borough in Allegheny County, about prior incidents involving Bowers, a person familiar with the investigation said.
Dormont Police Chief Michael Bisignani said there were mostly minor incidents from 1993 to 2004, including a traffic citation. Bowers was interviewed as a witness in a burglary case in 1996 and there was another incident in 2004 that police can't discuss because of the HIPAA privacy law.
Four hours before the shooting, Bowers posted about Trump. Minutes before allegedly storming inside the building, he logged onto Gab again and wrote to his followers.
"I can't sit by and watch my people get slaughtered," he wrote. "Screw your optics, I'm going in."
Gab denied supporting violence and said its mission is "to defend free expression and individual liberty online for all people." The company said it has backed up the suspect's profile data, suspended the account and contacted the FBI.
In a statement on Twitter Sunday, Gab said it is "under attack" and has been taken down by hosting providers, app stores and payment processors, after the events this weekend. It blames a smear campaign by the mainstream media, and says it will be up again once it transitions to a new hosting provider.
'Horrific crime scene'
Robert Jones, the FBI special agent in charge of the Pittsburgh office, called the shooting "the most horrific crime scene" he'd witnessed in 22 years with bureau.
The day began as a peaceful morning, with dozens of people filing inside the synagogue to celebrate Shabbat services with three congregations: Tree of Life, Dor Hadash and New Light.
Rabbi Myers recounted the moments of horror after the first gunshots rang out.
"At that point, I instructed my congregants to drop to the floor, do not utter a sound and do not move. Our pews are solid oak, perhaps there's some protection there. I quickly tried to usher some up to the front ... toward exits or a closet, some place they could hide, some place safe. I turned back to see if I could help the remaining people in the back of my congregation. At that time I could hear the gunfire getting louder. It was no longer safe to be there. I had to leave them."
Authorities on Sunday released the names of the 11 victims, all of whom were from Pennsylvania. They included a married couple, a pair of brothers and a beloved physician.
Joyce Fienberg, 75, Rose Mallinger, 97, Jerry Rabinowitz, 66, Cecil Rosenthal, 59, David Rosenthal, 54, Daniel Stein, 71, Melvin Wax, 88, and Irving Younger, 69, were from Pittsburgh. Richard Gottfried, 65, was from Ross Township and Bernice Simon, 84, and Sylvan Simon, 86, were from Wilkinsburg, Allegheny County Chief Medical Examiner Karl Williams said.
The Simons had married in the same synagogue in 1956, according to an announcement in the Pittsburgh Post-Gazette that year.
Four patients remain hospitalized. A 61-year-old woman is in stable condition; a 70-year-old man is in critical condition; a 55-year-old male police officer is in stable condition; and a 40-year-old male officer is in critical condition. A 27-year-old male officer was released from UPMC Mercy, according to Paul Wood, vice president and chief communications officer for UPMC Presbyterian.
Suspect had several firearms
Police said Bowers used a Colt AR-15 rifle and three Glock .357 handguns during the attack. He legally purchased the three Glock .357s, a law enforcement official familiar with the investigation told CNN. It's not clear whether the AR-15 was purchased legally.
The issue has reignited the debate about firearms. Tree of Life congregant Fred Rabner, Jesse Rabner's father, told CNN's "New Day" on Monday that "there's no sense in what happened" in Squirrel Hill and at other sites of mass shootings.
"We are going to have to do something to address automatic weapons that can take out an entire congregation in seconds. There's no rational reason to have that type of weapon in such hands as we saw here. And until we unify and address that issue as a country, we can't heal."
Jewish organizations said the violence at Tree of Life synagogue underscored the dangers of unchecked hatred in a time when anti-Semitic acts are on the rise.
The shooting drew sympathy from the Israeli government and its people. Israeli Prime Minister Benjamin Netanyahu spoke on the phone with Pennsylvania Gov. Tom Wolf on Sunday to express his condolences, and Israeli Diaspora Affairs Minister Naftali Bennett traveled to Pittsburgh for Sunday's service.
Adam Hertzman, director of marketing for the Jewish Federation of Pittsburgh, said it was too early to say if the community will add permanent security to synagogues in the area.
"Our focus at the moment is on mourning those who have passed and trying to comfort the people who are bereaved," Hertzman said.