Robert Bowers, 46, from the Baldwin suburb, surrendered to the authorities after shooting Tree of Life in the synagogue on Saturday morning. It is believed that he made anti-Semitic statements during the filming and specifically targeted Jews in social media sites that are a focus of the investigation, according to a federal police officer.
Bowers faces a total of 29 allegations that have left the Squirrel Hill area and the rest of the nation is stunned.
Pittsburgh Public Safety Director Wendell Hissrich told reporters, "These incidents usually happen in other cities."  "The nightmare is haunting the city of Pittsburgh today," he said.
Bowers is accused in eleven cases of using a firearm to commit murder, and multiple counts of two hate crimes: obstructing religious beliefs resulting in death and obstruction of religious beliefs, resulting in bodily harm to a public security official leads.
"The violent crimes are based on federal civil rights laws that prohibit hate crimes," said US Attorney Scott W. Brady and Bob Jones, FBI Special Representative for Pittsburgh's Bureau, in a statement.
Six people were injured as a result of the shootings, Hissrich said, four of them were police officers who responded to the scene. No children were among the dead, he said.
"It's a very horrific crime scene," he said. "It's one of the worst I've seen."
Shot just before 1
The violence on Saturday mornings shook the city and the historic Jewish neighborhood the synagogue, described by a parishioner as "close-knit" was designated.
Jim Waite, who lives across the street, said he had gone outside after a tumult. He assumed it was a car accident. A police car flew past him; another officer screamed to go inside. Waite said he heard more than five – possibly nine – shots from his house.
He said he could hear cries from the synagogue.
The Allegheny County Emergency Operations Center received calls from an active shooter at 9:54 pm ET, Hissrich told reporters. Officers were sent a minute later.
According to FBI Jones, the suspect was about to leave when he met a Pittsburgh police officer who "engaged" him. The officer was later injured, and the suspect returned to the synagogue where he hid from SWAT officers arriving on the scene.
Overall, two policemen and two SWAT officers were injured in the confrontation, Hissrich said. According to the public security department of the city, three of them were shot dead.
The suspect suffered multiple gunshot wounds and is in fair condition.
Investigators have found a rifle and three small arms from the site of the shooting, Jones said. The authorities believe that the suspect acted alone, and he said that the law enforcement authorities had no knowledge of Bowers prior to the shooting.
US Attorney General Jeff Sessions said in a statement on Saturday afternoon that the Department of Justice would "file hate crimes and other criminal charges against the defendant, including charges that could lead to the death penalty."
Five victims were treated in two Pittsburgh hospitals, according to Paul Wood, a spokesman for the University of Pittsburgh Medical Center. Four victims were treated at UPMC Presbyterian and one victim was treated at UPMC Mercy. One person was treated and released by Presbyterian.
Social media posts are part of investigation
A law enforcement agency told CNN that investigators believe a report on Gab, a social media platform, believed anti-Semitic views belonged to Bowers. The language on the account coincides with the alleged motives behind the shootings, the source said.
His last sinister post was made at 9:49 am, just five minutes before the police were notified of the shootout.
"I can not sit by and watch my people being slaughtered," Bowers wrote. "Screw your optics, I'm going in."
Bowers' Anti Semitic Comments have also fueled other hate speech he has spread through Gab, who has portrayed himself as an alternative to Twitter and imposes almost no content restrictions.
In a post, Bowers claimed that Jews helped transport members of migrant caravans. He believed that those in the migrant caravans were violent because they tried to leave countries by force. And Bowers repeatedly called them "invaders."
"I have noticed a change in the people saying" illegals "who now say" invaders "," read a post six days before shooting. "I like this."
Among The vitriolic statements are also criticizing President Donald Trump, in which Bowers suggested the president was surrounded by too many Jewish people.
"Trump is surrounded by k ****," "Things will stay the course," read a post about Gab, using a derogatory term to describe Jews.
About four hours before shooting, Bowers commented on a post saying he did not vote for Trump.
In a statement, Gab denied "all acts of terrorism and violence" and said that his job was to defend freedom of expression and individual freedom for all online.
After being alerted to the profile of the suspect on the platform, Gab said he backed up the data, The account was suspended and the FBI contacted
Bowers also provided photos on his gab account with his small arms collection, including several clips and landmarks.
On September 20, Bowers released images of shooting targets, of which He said they were targets from July 2017 with a Walther PPQ handgun
Shooting "Trump says
The FBI will be the leading investigative body," said Hissrich.  Trump told reporters at Andrews Joint Base in Maryland that the shooting was a "horrible, horrible thing.
"If there was an armed guard in the temple, they could have stopped him," Trump said before fleeing to Indianapolis.
After landing, Trump told reporters the shooting was "an anti-Semitic crime."
"We learn a lot about it. It definitely looks like it's an anti-Semitic crime, and that's something you would not believe it could still go on. "
Trump said in a tweet earlier that shooting was" far more devastating as originally assumed. "
Gov. Tom Wolf continued to tell Twitter that it was a "serious situation" and that the Pennsylvania State Police supported local first responders.
"This is an absolute tragedy," Wolf said in another tweet. "These senseless acts of violence are not what we Americans are, and right now I focus on the victims and their families and make sure law enforcement agencies have all the resources they need."
Alcohol Bureau agents, Tobacco, firearms and explosives responded to the shooting, according to the Philadelphia of the ATF
Security was a "big concern" for the community
The Synagogue of the Tree of Life is a conservative Jewish community, the museum's website says in Squirrel Hill, a historic Jewish community The synagogue will have a Sabbath service at 9:45 am on Saturday, the website said.
Conservative Judaism is one of the most important denominations of religion, the word conservative is not a political signature.
Michael Eisenberg, the immediate past president of the Tree of Life community, said three communities – Tree of Life, New Light, and Dor Hadash – would have been in the building on a typical Saturday at the same time.
Normally, about 40 people would visit the tree of life in the "main part of the building," Eisenberg said. In the basement, the service of New Light would also have 30 to 40 people. And the Dor Hadash community in the Rabbi's study has about 15 people, he said.
When he was the President of the Assembly, security was a "major concern," Eisenberg said.
The community has been working with the Department of Homeland Security to assess their exit routes, he said, consulting a securities expert from the Jewish Federation to find out what to do in an active shoot-out situation.
"We worked with the other synagogues on what to do when something terrible happens," he said.
In the July post, titled "We deserve better," Myers said he feared school shootings would continue without a "dramatic turn" in this year's midterm elections "Unless it's a dramatic one Turning in the middle I fear that the status quo will remain unchanged and shootings at school will resume. I should not include in my daily morning prayers that God should watch over and protect my wife and daughter, both teachers. " Wrote Myers. "Where are our leaders?"
US anti-Semitic incidents increased in 2017
A number of other figures and organizations, such as the US Holocaust Memorial Museum, condemned the violence and expanded their sympathy for the victims and their families.
"The museum reminds all Americans of the dangers of unbridled hatred and anti-Semitism that must be encountered wherever they occur, and calls on all Americans to actively promote social solidarity and respect the dignity of all people," so the holocaust museum said in a statement.
In a statement on Saturday, the ADL said the attack was considered the deadliest of the Jewish community in US history.
"It is simply unreasonable for Jews to be targeted during the service on a Sabbath morning," it said, "and unthinkable that it would happen in the United States today."