Eleven Prayers and a Post on Gab
Before killing 11 worshippers at Pittsburgh's Tree of Life synagogue in October 2018, the gunman had immersed himself in antisemitic content on the fringe network Gab. His federal trial five years later made the platform's role central evidence.
On the morning of Oct. 27, 2018, a gunman entered the Tree of Life synagogue in Pittsburgh's Squirrel Hill neighborhood during Shabbat services and opened fire, killing 11 worshippers and wounding others, including responding police officers. It was the deadliest antisemitic attack in U.S. history, according to PBS NewsHour.
On the morning of the attack, the gunman, Robert Bowers, posted a final message on Gab, an alt-tech social network popular with the far right. “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,” he wrote, referring to HIAS, the Jewish refugee-resettlement group formerly known as the Hebrew Immigrant Aid Society. The Southern Poverty Law Center's Hatewatch, which analyzed his account, reported that he made the post on “Saturday morning before Bowers began his attack.”
A record built on a fringe platform
Gab launched in 2016 as an unrestricted-speech alternative to Twitter and Facebook and became a gathering point for extremist users, the Southern Poverty Law Center found. In its analysis of Bowers' account, the group reported that “in the 19 days before Bowers carried out his act of mass murder, he posted or reposted memes and comments at least 68 times” — a stream centered on antisemitic conspiracy theories that cast Jews as enabling immigration to harm white Americans.
Bowers' activity was public and archived before his account was deactivated, leaving a documented trail investigators and journalists could reconstruct. He had “extensively posted, shared or liked antisemitic and white supremacist content on Gab … and praised Hitler and the Holocaust,” PBS NewsHour reported.
The platform as evidence
Bowers' online record became central to the case against him. His Gab profile carried the tagline “jews are the children of satan. (john 8:44),” and his posts included slurs and calls for violence against Jews, the Anti-Defamation League documented. When the case went to trial in 2023, prosecutors placed that record at the center of their argument.
On June 16, 2023, a federal jury found Bowers guilty on all 63 counts, including hate crimes resulting in death and obstructing the free exercise of religious beliefs resulting in death, according to PBS NewsHour. On Aug. 2, 2023, the same jury recommended a death sentence, and Bowers was subsequently sentenced to death, PBS NewsHour reported.
A pattern that outlived the case
The Tree of Life attack has become a frequently cited example of a documented sequence: a person radicalized in online spaces built for unmoderated speech, whose escalating posts preceded real-world violence and whose final message was published on the same platform. Researchers who study extremism note that fringe networks marketed on free-speech grounds have repeatedly hosted such trajectories with little intervention.
The reconstruction of Bowers' Gab history — from a years-long stream of hate to a post made the morning of the killings — illustrated for a jury how an online record can trace the path to an attack, even after an account is taken down.