Context:

A North Carolina teenager, 17-year-old Sarah Santiago, faces adult murder and conspiracy charges for allegedly aiding two California teens who carried out a deadly May 18 attack at the Islamic Center of San Diego. Prosecutors say the defendants planned to livestream and disseminate the attack and that Santiago helped by agreeing to record and share the footage and by sending a white-supremacist patch to one gunman. Her defense argues prosecutors have not provided enough detail on communications or the alleged agreement, despite a formal bill-of-particulars request and a court hearing. The case centers on whether Santiago's anticipated involvement meets the legal threshold for aiding and abetting, with potential consequences mirroring those of the principal crime. A trial timeline remains uncertain as officials continue to clarify the allegations and evidence.

Dive Deeper:

• Santiago, a 17-year-old from North Carolina, is charged as an adult with three counts of murder by aiding and abetting and one count of conspiracy in connection with the San Diego mosque attack.

• Prosecutors allege she agreed in advance to record and distribute a livestream of the attack and to disseminate the shooters' white-supremacist writings; they also accuse her of sending a white-supremacist patch to one of the gunmen.

• Her attorney filed a bill of particulars seeking more information on how and when Santiago communicated with the shooters and details of the alleged livestream agreement, asking the court to compel disclosure without requiring the actual evidence.

• The defense argues the information is essential for a fair defense, while prosecutors have not yet responded to the request and a hearing has been scheduled.

• The two California attackers, Cain Clark and Caleb Vazquez (the latter described as autistic by his family), killed three people at the mosque before dying by suicide; authorities say they also plotted further targets, including a Jewish temple and a high school.

• The incident followed a broader pattern of extremist writings and conduct linked to the attackers, with one guard providing initial protection and safety at the scene.

• The case demonstrates legal questions about how far a defendant’s preparatory actions and intent must go to constitute aiding and abetting, and what disclosures are necessary for a defensible case.