A 17-year-old girl from North Carolina has been charged with murder over a shooting at the Islamic Center of San Diego, despite having been on the other side of the United States when the attack took place. Sarah Lindsey Santiago is accused of coordinating remotely with two California teenagers who carried out the shooting, allegedly helping to livestream the massacre and circulate the gunmen's manifesto. The case is notable for testing the boundaries of accomplice liability, as prosecutors are charging someone who never physically attended the crime scene as a principal in the killings.

Santiago faces three counts of first-degree murder and one count of conspiracy to commit murder over the 18 May attack, carried out by 17-year-old Cain Clark and 18-year-old Caleb Vazquez, who killed three people before being found dead from self-inflicted gunshot wounds. Prosecutors allege Santiago, who knew the pair only online, recorded and shared their GoPro livestream, sent Vazquez a patch bearing a Nazi symbol, and watched the attack unfold in real time; she is being charged as an adult. District Attorney Jim O'Neill described the trio as "an echo chamber of hate," saying court documents show they also plotted attacks on a synagogue and Black students at a school. Santiago's lawyer maintains she is innocent, calling the case a "major tragedy" touching on youth, social media and mental health.