The sister of a slain federal security guard is suing Facebook’s parent company, Meta, over its part in helping radicalize the two men who shot and killed her brother.

David Patrick Underwood and his partner were guarding a federal building in Oakland on May 29, 2020, while nearby riots prompted by the police killing of George Floyd were underway. While standing guard, Underwood and his partner were shot at during a drive-by attack conducted by Steven Carrillo, an Air Force sergeant, and Robert Alvin Justus Jr. Underwood died as a result of his injuries, and his partner was left wounded.

Underwood’s sister filed the wrongful death lawsuit against Meta in Alameda County Superior Court, claiming that the company’s social networking site helped connect the two extremists. Angela Underwood Jacobs shared in a statement, “Facebook bears responsibility for the murder of my brother. As the lawsuit alleges, Facebook knowingly promoted inflammatory and violent content and connected extremists who plotted and carried out the killing of my brother."

Her lawsuit alleges that Facebook used its algorithms to help connect users who showed interest in extremism and that the men responsible for her brother’s death were connected through the platform’s group, “boogaloo,” an extremist anti-government group.

Angela Underwood Jacob’s attorney Ted Leopold shared, “We believe and intend to show that Facebook’s conduct has led to a rise in extremism throughout the world and acts of real-world violence, including the murder of Officer Underwood.” Leopold adds, “It is time that Facebook is finally held accountable for its actions.”

Federal prosecutors detailed that the two men were connected through Facebook and intended to meet up on the evening Underwood was shot to advance their agenda on retaliation against law enforcement. Messages obtained during the investigation show that the two men decided to meet up with each other under the cover of the social justice riot which unfolded nearby. The messages detail that Carrillo planned to shoot at Underwood and his partner using a homemade assault weapon.

Following the shooting, the two men fled. However, Carrillo was arrested just eight days later after he shot and killed a Santa Cruz Sheriff’s sergeant and wounded four other officers. Carrillo has pled not guilty to both crimes.

Meta has fired back against the allegations that Facebook bears responsibility for the crime. "We’ve banned more than 1,000 militarized social movements from our platform and work closely with experts to address the broader issue of internet radicalization. These claims are without legal basis,” shared Kevin McAlister, a spokesman for Meta.

Since Underwood’s death, Facebook has vowed to remove groups from their platform that tout extremism through far right-wing ideologies. Despite this promise, the lawsuit details that extremist groups including the boogaloo movement continue to exist on Facebook.

In her wrongful death lawsuit, Underwood’s sister is seeking at least $25,000 in damages.