Sarah Lindsey Santiago of Winston-Salem was indicted Monday on three counts of first-degree murder and one count of conspiracy to commit first-degree murder for allegedly aiding and abetting 17-year-old Cain Clark and 18-year-old Caleb Vazquez before and during their May 18 attack on the Islamic Center in Clairemont. Prosecutors allege Santiago had agreed beforehand to help preserve and spread the gunmen's violence by recording their livestream and distributing both the footage and a manifesto they wanted released to the public.
The charges immediately raise an obvious question: How can a teenager sitting across the country, who prosecutors do not accuse of firing a gun or even being physically present in California, be charged with murdering three people in San Diego?
The answer lies in the unusually broad consequences of accomplice liability and, more specifically, North Carolina's law of aiding and abetting. Prosecutors are not alleging that Santiago merely watched the shooting online or knew something terrible was going to happen and failed to report it. Their case alleges something substantially more consequential: that she knowingly became part of the plan before the shooting and performed an assigned role intended to help the attackers accomplish their objectives. That distinction could determine whether an extraordinary prosecution ultimately results in an extraordinary conviction.
According to the indictment and statements from Forsyth County District Attorney Jim O'Neill, Clark and Vazquez wanted to accomplish two things on May 18: kill as many people as possible and ensure their violence was recorded, preserved and disseminated to an online audience. Authorities allege Santiago agreed before the attack to record the livestream being transmitted by the gunmen, distribute the recording afterward and publish their manifesto. She then allegedly carried out those tasks. Santiago is also accused of purchasing a patch bearing a white-supremacist symbol and sending it to one of the attackers, who prosecutors say wore it during the massacre.
Those allegations transform the legal analysis considerably. Watching a crime, even knowing beforehand that it might happen, is not automatically equivalent to committing it. North Carolina's Supreme Court has held that aiding and abetting requires more: the defendant must knowingly assist or encourage the perpetrator and share the requisite criminal intent. The state's courts have described accomplice liability as requiring both conduct that assists, promotes, encourages or instigates criminal activity and the mental state necessary to intentionally facilitate the crime.
In a 2010 decision, the North Carolina Supreme Court summarized the doctrine more precisely: another person must have committed the crime; the defendant must have knowingly advised, instigated, encouraged, procured or aided that person; and the defendant's actions or statements must have caused or contributed to the commission of the crime.
That is considerably different from the suggestion made during Monday's news conference that Santiago's failure to warn authorities could itself make her responsible for the killings. FBI Charlotte Special Agent in Charge Reid Davis emphasized that the teenager allegedly had "multiple opportunities" to alert law enforcement about the plot and did not do so. But legally, prosecutors will have to prove substantially more than silence or failure to intervene to establish aiding-and-abetting liability for first-degree murder.
North Carolina precedent makes that distinction explicit. The state's Supreme Court has held that a person is not guilty simply because he or she is present while a crime occurs, even if that person privately approves of what is happening. Instead, there must be assistance, active encouragement or some communication of an intention to assist, although that communication can be inferred from conduct and the relationship between the participants.
Santiago's alleged advance agreement to preserve and distribute the attackers' livestream and manifesto is therefore central to the prosecution. If the state proves that Clark and Vazquez planned the massacre with the understanding that Santiago would help broadcast and amplify it, prosecutors can argue that publicity was not something she provided after an already-completed crime; it was part of the attack's purpose from the beginning. O'Neill made precisely that argument Monday, saying the gunmen's plan was not merely to kill but to have their "carnage and destruction" recorded, livestreamed and disseminated.
The allegations also reveal just how deeply investigators have penetrated an online network surrounding Clark and Vazquez since the shooting. FBI officials say investigators have conducted more than 100 interviews, executed more than 30 search warrants and examined more than four million messages during the continuing investigation.
Authorities say the two San Diego-area teenagers met online and became immersed in an extremist subculture before discovering they lived relatively close to one another. Their writings drew from neo-Nazi and white-supremacist ideology and expressed hatred toward Muslims, Jewish people, Black people, LGBTQ+ people, women and people across the political spectrum, while praising previous mass killers and discussing a desire to accelerate social collapse.
Monday's announcement revealed that their ambitions allegedly extended substantially beyond what actually happened at the Islamic Center. According to prosecutors, Clark and Vazquez intended to follow the mosque massacre with attacks on a nearby Jewish congregation and then a predominantly Black high school. The indictment identifies the second intended target as Kehilat Ariel Messianic Synagogue, located less than two miles from the Islamic Center. Authorities have not publicly identified the school. That planned sequence makes the intervention of Islamic Center security guard Amin Abdullah even more consequential.
On May 18, Clark and Vazquez arrived heavily armed at the mosque at approximately 11:43am while roughly 140 people, many of them schoolchildren, were on the property. Abdullah recognized the threat, initiated lockdown procedures and exchanged gunfire with the attackers. Authorities revealed Monday that Abdullah managed to shoot and wound Clark during the confrontation, a detail that had not previously been publicly disclosed.
Abdullah was killed, along with 78-year-old Mansour Kaziha, a longtime founder and caretaker of the mosque, and 57-year-old Nadir Awad, who lived nearby and ran toward the Islamic Center after hearing gunfire. The attackers subsequently fled. They fired at a landscaper several blocks away without striking him before being found dead from self-inflicted gunshot wounds inside their vehicle roughly a half-mile from the mosque. Whatever plans they allegedly had for additional targets ended there.
The new indictment suggests, however, that the physical attack in San Diego was only one part of a digital operation extending far beyond Southern California. Authorities say Clark and Vazquez wore GoPro cameras to livestream the massacre. Investigators ultimately determined that three people were watching the original livestream, although initially they knew little about one of them beyond the fact that she appeared to be located in the Eastern time zone. That trail eventually led investigators to Winston-Salem and Santiago.
Exactly how Santiago allegedly met Clark and Vazquez, how long the three communicated, what their complete conversations contain and precisely when she learned that an actual mass shooting was planned have not yet been publicly disclosed. Those questions will likely become critical as the prosecution moves forward. Her defense has already rejected the allegations.
"At this time, I can confirm that my client is innocent of all these charges," attorney Alan Doorasamy Sr. told the Associated Press, adding that he had not yet received the government's evidence concerning his client.
The prosecution will therefore ultimately have to prove not merely that Santiago interacted with two extremists, possessed abhorrent beliefs, watched their attack or distributed their material, but that her conduct and state of mind satisfy North Carolina's requirements for accomplice liability.
The geographic distance presents another unusual feature, but it does not necessarily prevent North Carolina from prosecuting the case. North Carolina law expressly provides that when a charged offense occurs partly inside and partly outside the state, the defendant may be tried there so long as the person has not already been placed in jeopardy for the identical offense elsewhere. If prosecutors prove that Santiago entered the alleged agreement and performed her part of the operation from North Carolina, the state has a statutory basis for asserting jurisdiction despite the killings themselves occurring in California.
The fact that Santiago was only 17 at the time presents another complicated issue. North Carolina generally treats people younger than 18 as juveniles, but serious felony charges can move into adult court. Under the state's current system, a 16- or 17-year-old accused of the most serious felony offenses can be prosecuted in Superior Court, and first-degree murder is a Class A felony. Santiago has been indicted and is being prosecuted as an adult.
That does not mean her age becomes irrelevant if she is convicted. Because Santiago was under 18 when the alleged crimes occurred, North Carolina's special juvenile-murder sentencing statutes would apply. A juvenile convicted of first-degree murder can face life imprisonment, but life without parole is not automatically imposed. For first-degree murder convictions other than those based solely on felony murder, a judge must conduct a sentencing hearing to determine whether life without parole or life with the possibility of parole is appropriate, considering youth-related mitigating circumstances. Under state law, "life with parole" for a juvenile means eligibility for parole after serving at least 25 years.
In other words, reports that Santiago simply "faces life without parole" omit an important legal qualification: that sentence is potentially available, but because she was a minor at the time of the alleged offenses, it would require the individualized sentencing process created for juvenile murder defendants.
The decision to prosecute her in North Carolina was itself deliberate. O'Neill said federal authorities evaluated the case but concluded the potential federal punishment for Santiago's alleged conduct could amount to only several years. Investigators instead approached Forsyth County prosecutors about pursuing charges under state law, where accomplice liability potentially exposes her to punishment for the murders themselves.
"The law in North Carolina is clear," O'Neill said Monday. A person who aids and abets another person in committing a crime, he said, can be found guilty of that crime even without personally performing the acts constituting it.
That theory also explains why Santiago faces three murder counts rather than a single generalized charge related to the attack. Prosecutors contend she aided the underlying criminal enterprise that resulted in the deaths of Abdullah, Kaziha and Awad; each death therefore forms the basis of a separate murder allegation.
The case could become a consequential test of how traditional accomplice-liability principles apply to a distinctly modern form of mass violence in which participants can allegedly occupy different roles across thousands of miles: gunmen at the physical scene, viewers receiving a livestream, and online associates assigned to preserve or amplify propaganda after an attack.
It is equally important, however, to distinguish that theory from criminalizing spectatorship. Authorities have said three people watched the initial livestream, and it remains unclear whether the other viewers have been identified or are suspected of participating in the plot. Nothing announced Monday suggests that simply viewing the stream would, by itself, expose someone to murder liability.
The alleged advance agreement is what separates Santiago's case as prosecutors currently describe it.
The arrest also sheds new light on the extraordinary volume of digital evidence investigators have been processing since May. When San Diego and federal officials initially described Clark and Vazquez as teenagers radicalized online, the extent to which they had communicated with like-minded people elsewhere remained largely unknown. Santiago's indictment is the first publicly announced arrest of another person allegedly connected to the attack.
Imam Taha Hassane told the San Diego Union-Tribune that mosque leaders have long suspected the two shooters were not operating entirely in isolation and welcomed the arrest while urging investigators to determine whether others were involved.
That investigation remains active.
There were warning signs involving at least one of the gunmen well before May 18. More than a year before the massacre, High Tech High officials contacted police concerning Vazquez after troubling behavior that reportedly included fascination with mass shootings and telling a friend not to attend school the following day. Vazquez was placed on a 72-hour involuntary mental-health hold, and his parents subsequently stored the family's 26 firearms with a licensed gun dealer.
By May 2026, investigators say Clark and Vazquez had accumulated access to firearms and tactical equipment, developed detailed extremist writings, devised multiple targets and arranged to broadcast their violence.
Hours before the attack, Clark's mother reported her son missing, suicidal and potentially armed after discovering weapons and a vehicle were gone. Police issued a regional alert, but the teenagers reached the Islamic Center before officers intercepted them.
Santiago's alleged role now adds another layer to that timeline: prosecutors contend someone across the country knew enough beforehand to arrange for the attack's digital preservation and dissemination.
Whether the evidence proves that allegation beyond a reasonable doubt will ultimately be decided in court. Santiago has pleaded innocence through her attorney, the complete communications underlying the prosecution have not been released, and an indictment establishes charges rather than guilt.
She is currently being held without bond and is scheduled to return to court September 21.
For the Islamic Center of San Diego, Monday's arrest comes more than three months after a morning that permanently changed the community. Abdullah, Kaziha and Awad were killed, but the approximately 140 people inside the complex survived, and prosecutors now say the attackers never reached two additional targets they allegedly intended to strike afterward.
The investigation that began in a Clairemont parking lot has since expanded through millions of messages, dozens of warrants and interviews across the country. With the first outside alleged participant now facing the same murder charges as if she had been standing alongside the gunmen, authorities are signaling that they believe the May 18 attack extended well beyond the two teenagers who physically carried it out.
And the prosecution of a 17-year-old girl in North Carolina may ultimately determine just how far criminal responsibility for a livestreamed mass killing can extend.
This is a developing story and will be updated as additional information becomes available.
Originally published August 31, 2026.
The new indictment suggests, however, that the physical attack in San Diego was only one part of a digital operation extending far beyond Southern California. Authorities say Clark and Vazquez wore GoPro cameras to livestream the massacre. Investigators ultimately determined that three people were watching the original livestream, although initially they knew little about one of them beyond the fact that she appeared to be located in the Eastern time zone. That trail eventually led investigators to Winston-Salem and Santiago.
Exactly how Santiago allegedly met Clark and Vazquez, how long the three communicated, what their complete conversations contain and precisely when she learned that an actual mass shooting was planned have not yet been publicly disclosed. Those questions will likely become critical as the prosecution moves forward. Her defense has already rejected the allegations.
"At this time, I can confirm that my client is innocent of all these charges," attorney Alan Doorasamy Sr. told the Associated Press, adding that he had not yet received the government's evidence concerning his client.
The prosecution will therefore ultimately have to prove not merely that Santiago interacted with two extremists, possessed abhorrent beliefs, watched their attack or distributed their material, but that her conduct and state of mind satisfy North Carolina's requirements for accomplice liability.
The geographic distance presents another unusual feature, but it does not necessarily prevent North Carolina from prosecuting the case. North Carolina law expressly provides that when a charged offense occurs partly inside and partly outside the state, the defendant may be tried there so long as the person has not already been placed in jeopardy for the identical offense elsewhere. If prosecutors prove that Santiago entered the alleged agreement and performed her part of the operation from North Carolina, the state has a statutory basis for asserting jurisdiction despite the killings themselves occurring in California.
The fact that Santiago was only 17 at the time presents another complicated issue. North Carolina generally treats people younger than 18 as juveniles, but serious felony charges can move into adult court. Under the state's current system, a 16- or 17-year-old accused of the most serious felony offenses can be prosecuted in Superior Court, and first-degree murder is a Class A felony. Santiago has been indicted and is being prosecuted as an adult.
That does not mean her age becomes irrelevant if she is convicted. Because Santiago was under 18 when the alleged crimes occurred, North Carolina's special juvenile-murder sentencing statutes would apply. A juvenile convicted of first-degree murder can face life imprisonment, but life without parole is not automatically imposed. For first-degree murder convictions other than those based solely on felony murder, a judge must conduct a sentencing hearing to determine whether life without parole or life with the possibility of parole is appropriate, considering youth-related mitigating circumstances. Under state law, "life with parole" for a juvenile means eligibility for parole after serving at least 25 years.
In other words, reports that Santiago simply "faces life without parole" omit an important legal qualification: that sentence is potentially available, but because she was a minor at the time of the alleged offenses, it would require the individualized sentencing process created for juvenile murder defendants.
The decision to prosecute her in North Carolina was itself deliberate. O'Neill said federal authorities evaluated the case but concluded the potential federal punishment for Santiago's alleged conduct could amount to only several years. Investigators instead approached Forsyth County prosecutors about pursuing charges under state law, where accomplice liability potentially exposes her to punishment for the murders themselves.
"The law in North Carolina is clear," O'Neill said Monday. A person who aids and abets another person in committing a crime, he said, can be found guilty of that crime even without personally performing the acts constituting it.
That theory also explains why Santiago faces three murder counts rather than a single generalized charge related to the attack. Prosecutors contend she aided the underlying criminal enterprise that resulted in the deaths of Abdullah, Kaziha and Awad; each death therefore forms the basis of a separate murder allegation.
The case could become a consequential test of how traditional accomplice-liability principles apply to a distinctly modern form of mass violence in which participants can allegedly occupy different roles across thousands of miles: gunmen at the physical scene, viewers receiving a livestream, and online associates assigned to preserve or amplify propaganda after an attack.
It is equally important, however, to distinguish that theory from criminalizing spectatorship. Authorities have said three people watched the initial livestream, and it remains unclear whether the other viewers have been identified or are suspected of participating in the plot. Nothing announced Monday suggests that simply viewing the stream would, by itself, expose someone to murder liability.
The alleged advance agreement is what separates Santiago's case as prosecutors currently describe it.
The arrest also sheds new light on the extraordinary volume of digital evidence investigators have been processing since May. When San Diego and federal officials initially described Clark and Vazquez as teenagers radicalized online, the extent to which they had communicated with like-minded people elsewhere remained largely unknown. Santiago's indictment is the first publicly announced arrest of another person allegedly connected to the attack.
Imam Taha Hassane told the San Diego Union-Tribune that mosque leaders have long suspected the two shooters were not operating entirely in isolation and welcomed the arrest while urging investigators to determine whether others were involved.
That investigation remains active.
There were warning signs involving at least one of the gunmen well before May 18. More than a year before the massacre, High Tech High officials contacted police concerning Vazquez after troubling behavior that reportedly included fascination with mass shootings and telling a friend not to attend school the following day. Vazquez was placed on a 72-hour involuntary mental-health hold, and his parents subsequently stored the family's 26 firearms with a licensed gun dealer.
By May 2026, investigators say Clark and Vazquez had accumulated access to firearms and tactical equipment, developed detailed extremist writings, devised multiple targets and arranged to broadcast their violence.
Hours before the attack, Clark's mother reported her son missing, suicidal and potentially armed after discovering weapons and a vehicle were gone. Police issued a regional alert, but the teenagers reached the Islamic Center before officers intercepted them.
Santiago's alleged role now adds another layer to that timeline: prosecutors contend someone across the country knew enough beforehand to arrange for the attack's digital preservation and dissemination.
Whether the evidence proves that allegation beyond a reasonable doubt will ultimately be decided in court. Santiago has pleaded innocence through her attorney, the complete communications underlying the prosecution have not been released, and an indictment establishes charges rather than guilt.
She is currently being held without bond and is scheduled to return to court September 21.
For the Islamic Center of San Diego, Monday's arrest comes more than three months after a morning that permanently changed the community. Abdullah, Kaziha and Awad were killed, but the approximately 140 people inside the complex survived, and prosecutors now say the attackers never reached two additional targets they allegedly intended to strike afterward.
The investigation that began in a Clairemont parking lot has since expanded through millions of messages, dozens of warrants and interviews across the country. With the first outside alleged participant now facing the same murder charges as if she had been standing alongside the gunmen, authorities are signaling that they believe the May 18 attack extended well beyond the two teenagers who physically carried it out.
And the prosecution of a 17-year-old girl in North Carolina may ultimately determine just how far criminal responsibility for a livestreamed mass killing can extend.
This is a developing story and will be updated as additional information becomes available.
Originally published August 31, 2026.
