Robert Bowers cut short his time in high school, worked for a small trucking firm, and became enamored of extremist theories circulated online.

He moved through the Pittsburgh area, primarily the South Hills, leaving relatively little impression before he emerged Saturday as the suspect charged in the fatal shooting of 11 people at the Tree of Life Congregation in Squirrel Hill. Mr. Bowers' family has not communicated with the Pittsburgh Post-Gazette, but online resources suggest a troubled early life.

Robert Bowers, the suspect in the deadly shooting at the Tree of Life Synagogue in Pittsburgh.
Pennsylvania Department of Transportation via AP
Robert Bowers, the suspect in the deadly shooting at the Tree of Life Synagogue in Pittsburgh.

There were recent warning signs, but they may have been invisible, except to those in a remote corner of the social media landscape.

The Southern Poverty Law Center, which tracks the activities of extremists, on Monday released an analysis of Mr. Bowers' online social media activity.

The center found 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." Many of those reflected "antisemitic conspiracy theories that have long been in circulation among neo-Nazis and white nationalists," the center found.

The analysis indicated that Mr. Bowers seemed to be influenced by white nationalist fixations on the caravan of Central Americans moving through Mexico, and by fringe "white genocide" theories that Jews and minorities were, in combination, threatening whites with "extinction."

Mr. Bowers, in his posts, did not support President Donald Trump, and circulated memes characterizing the president as a puppet of Jewish interests, the analysis indicated.

Two days before the attack, Mr. Bowers reposted on Gab.com a meme expressing disappointment with the federal conspiracy and rioting indictments against some participants and organizers of the Rise Above Movement, in relation to the August 2017 Unite the Right rally that led to the death of one counter-protester. "First Trump came for the Charlottesville 4 but I kept supporting Trump because he is better than Hillary Clinton," it read, in part. "Then Trump came for me and the [sic] was no one left …"

In the last sentence posted on his Gab.com account — "Screw your optics, I'm going in" — Mr. Bowers was almost certainly referring to a debate in the white nationalist movement over whether adherents should be concerned with public opinion, according to the analysis.

Mr. Bowers, 46, of Baldwin Borough, is accused in the shooting deaths and charged with 29 federal counts, including obstruction of exercise of religious beliefs resulting in death and use of a firearm to commit murder during a crime of violence, among others.

He also faces charges at the state level, including 11 counts of homicide, six counts of attempted homicide, aggravated assault and ethnic intimidation.

An online family tree posted by a member of Mr. Bowers' extended clan indicates that his father was the late Randall G. Bowers. News reports from 1979 indicate that Randall G. Bowers, then 27, was charged in 1979 with rape, and was found six months later in a picnic area near the Tionesta Dam, dead from an apparently self-inflicted rifle wound to the chest.

The Baldwin-Whitehall School District on Monday confirmed that Mr. Bowers attended the district's high school, but not for four full years.

The only mention of Mr. Bowers the Pittsburgh Post-Gazette was able to find in his high school yearbooks was a junior year portrait, in Baldwin High School's 1989 yearbook. He is not listed as taking part in any clubs or activities, and classmates reached by the newspaper said they had no recollection of him.

According to one list of area trucking workers, Mr. Bowers has worked at B. Keppel Trucking in Pittsburgh's Fairywood neighborhood. No one answered phones or doors there on Monday morning.

In 2015, when Mr. Bowers was ticketed in Cranberry for operating a vehicle without the proper identification marker displayed, he was driving a white International truck owned by Pam Transport Inc., out of Tahlequah, Okla. According to the ticket, he was living then on Fieldcrest Drive in Whitehall. A Pam Transport spokeswoman could not be immediately reached for comment.

Although police say he possessed four guns at the time of the attack, he is not known among area firearms aficionados, according to several sources with deep knowledge of the Second Amendment community.

The school district, in a statement from Superintendent Randal A. Lutz, indicated that Mr. Bowers, attended the high school from August 1986 to November 1989. That timeline suggests that he did not graduate, but the district indicated that any other details are considered confidential.

"It is my firm belief that our focus must remain, not on the gunman, but on honoring the lives of the victims and offering our unwavering support to the victims' families," wrote Mr. Lutz. "I know the entire Baldwin-Whitehall community feels a deep sense of shock and sadness and we grieve together with the victims' families, our neighbors in Squirrel Hill and our friends in the Jewish faith."

He added: "By learning to see our classmates, coworkers, and neighbors as ourselves, we each take one step closer to living in a stronger, safer, and more loving community. When we value one another despite our differences, the idea of harming another becomes unthinkable."

Federal prosecutors have begun seeking approval to pursue the death penaltyfor Mr. Bowers, according to the U.S. attorney's office in Pittsburgh. City officials have called Saturday's attack the "darkest day in Pittsburgh's history."

Mr. Bowers appeared before U.S. Magistrate Judge Robert C. Mitchell Monday afternoon at the federal courthouse in Downtown.

Mr. Bowers, who authorities said went into the Tree of Life synagogue armed with an AR-15-style assault rifle and three handguns, was shot by police during Saturday's incident. He underwent surgery.

According to the affidavit of probable cause, Mr. Bowers told authorities while he was receiving medical treatment that "he wanted all Jews to die and also that they (Jews) were committing genocide to his people."

Authorities say Mr. Bowers also used a social networking site — Gab.com — to express hatred for Jews and immigrants in the weeks prior to Saturday's shootings.

Mr. Bowers was released from Allegheny General Hospital at 9:45 a.m., and was taken immediately to the federal courthouse, Downtown, for his initial appearance on hate crime charges and other charges related to Saturday's shooting at the Tree of Life synagogue in Squirrel Hill that left 11 dead and six others injured.