What we know about alleged Pittsburgh synagogue gunman Robert Bowers

The suspect in Saturday's mass shooting at a Pittsburgh synagogue is a 46-year-old man named Robert Bowers who posted virulent anti-Semitic messages on social media filled with slurs and conspiracy theories.

Two hours before a gunman burst into the Tree of Life synagogue and opened fire during Shabbat religious services, Bowers posted on chat site Gab.com about the Hebrew Immigrant Aid Society (HIAS), a non-profit that helps refugees and immigrants to the United States.

"HIAS likes to bring invaders in that kill our people. I can't sit by and watch my people get slaughtered. Screw your optics, I'm going in," wrote Bowers, a heavy-set, white man.

The gunman reportedly shouted anti-Semitic phrases during the shooting, which left 11 people dead and six injured, including four police officers.

The suspect, a Pittsburgh resident, was shot and is in fair condition at a hospital, authorities said.

Critic of diversity

Gab.com said in a statement that when it learned of the shooting suspect's profile on its site, it took "swift and proactive" action to contact law enforcement.

Gab, which promotes itself as a free-speech alternative to the more heavily policed Twitter and has been a popular gathering space for the alt-right, said it backed up the user data and suspended the account, then told the Federal Bureau of Investigation about the data held by the company.

• 'Brutally murdered simply because of their faith': 11 killed by gunman in Pittsburgh synagogue 

"Gab unequivocally disavows and condemns all acts of terrorism and violence," the company's statement said.

Bowers has an active firearms licence and has made at least six known gun purchases since 1996, a law enforcement official familiar with the investigation told CNN. He did not have a criminal record and was not known to police, law enforcement officials said on Saturday.

An archive of Bower's Gab posts since he joined the site in January showed an angry, anti-Semitic man who shared messages such as: "Daily Reminder: Diversity means chasing down the last white person."

About a month ago, he posted pictures showing what appeared to the results of his target practice at a shooting range, and a collection of three handguns that he called his "glock family."

Police said the suspect had three handguns and an assault-style rifle at the shooting. It's unclear whether they were the same handguns as the ones in the photo.

Bowers, who is a registered voter with "no affiliation" in Allegheny County, Pa., took aim in one post at U.S. President Donald Trump, accusing him of being a "globalist" who did nothing to stop the "infestation" of the United States by Jews.

"For the record, I did not vote for him nor have I owned, worn or even touched a MAGA hat," he wrote. MAGA is an acronym for Make America Great Again that is frequently used by Trump.