The self-proclaimed leader of a white supremacy group admitted in a guilty plea Tuesday that he threatened jurors and witnesses in the Pittsburgh Tree of Life synagogue massacre trial, the deadliest antisemitic attack in U.S. history.

Hardy Carroll Lloyd of Follansbee, West Virginia said he posted threats via social media, websites and emails during the federal hate crimes trial in Pittsburgh of Robert Bowers, the U.S. Attorney’s Office announced Tuesday. Lloyd pleaded guilty to obstruction of the due administration of justice.

On Oct. 27, 2018, Bowers drove to the Tree of Life synagogue in Pittsburgh’s Squirrel Hill neighborhood with multiple firearms and fired more than 100 rounds, ultimately killing 11 people and injuring seven others. Prosecutors said he was driven by long-held antisemitism and hatred of immigrants as he burst into the place of worship and shouted "All Jews must die" as he fired.

As part of his plea agreement, Lloyd, 45, stipulated that he intentionally chose the jurors and witnesses in the Bowers trial as his targets "due to the actual or perceived Jewish religion of the witnesses and the Bowers victims," officials said.

“It is absolutely reprehensible that the defendant threatened witnesses and jurors in the Tree of Life case, a tragedy that claimed innocent lives and emotionally scarred many in the Jewish community,” said Christopher Wray, director of the Federal Bureau of Investigation.

If the court accepts Lloyd’s agreement, he will be sentenced to 78 months in prison, which is expected to be the highest end of the sentencing range calculated under sentencing guidelines, officials said.

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“Hardy Lloyd attempted to obstruct the federal hate crimes trial of the deadliest antisemitic attack in American history,” said Attorney General Merrick Garland. “His guilty plea underscores that anyone who attempts to obstruct a federal trial by threatening or intimidating jurors or witnesses will be met with the full force of the Justice Department.”

Long history white supremacist group involvement

Lloyd was arrested for criminal charges related to obstruction of justice and witness tampering on Aug. 10, days after Bowers' trial concluded. 

The Anti-Defamation League said in August it had been tracking Lloyd and his white supremacist activities since at least 2003. 

According to the ADL, Lloyd has been associated with a number of white supremacist groups, many of which he created and were relatively small. Lloyd dubbed himself leader of the Church of Ben Klassen, a pseudo-religious white supremacist group, the ADL said. 

Synagogue shooter’s fate determined last month

Bowers, 50, was sentenced to death on Aug. 3 following a two-month trial.

A federal jury recommended his execution after finding him guilty on 63 criminal counts in June, including hate crimes resulting in death and obstruction of the free exercise of religion resulting in death.

It was the first federal death sentence to be imposed during President Joe Biden's administration.

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Bowers was one of the early adopters of the extremist-friendly social media site Gab. He posted on his account just before attacking the synagogue.

Following the massacre, the shooter bragged about what he did and told psychologists that he wished he had killed more people, Assistant U.S. Attorney Nicole Vasquez Schmitt told jurors in an opening statement.

Antisemitism on the rise — social media partly to blame

An annual survey by the ADL, which has been studying antisemitism in the U.S. since the 1960s, concluded the number of Americans who hold extensive antisemitic prejudice and believe in antisemitic tropes has doubled since 2019. 

One-fifth of people surveyed said they believe in six or more ideas the ADL describes as anti-Jewish tropes, the highest level the group has found in three decades. 

Two other studies from the ADL and the Tech Transparency Project, provided exclusively to USA TODAY, found the world’s biggest social media platforms not only host antisemitic and hateful content – they promote it and make it easier to find.

Facebook, Instagram and X, formerly Twitter, steer users to tropes and conspiracies, researchers found.

“This completely upends this notion that they are just neutral pipes, it’s just third-party content and therefore they are doing their best but they are not actually responsible for what’s happening,” ADL vice president Yael Eisenstat previously said.