Teen suspects in San Diego Islamic Center shooting could be tied to online extremist groups

CHICAGO (WLS) -- For months, the ABC7 I-Team has been reporting on sadistic online groups that sow chaos in communities across the globe. Sources tell ABC News the now-dead San Diego Islamic Center shooting suspects may have been connected to similar nihilistic violent extremism online. Those connections should have triggered immediate intervention according to a former Department of Homeland Security expert.

"As with most of these cases, these people were on the radar screen, meaning that their behaviors were being noticed, and often those behaviors of concern were being reported," said John Cohen, Former Assistant Department of Homeland Security Secretary for Counterterrorism.

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Cohen told the I-Team when there are reports of troubling interests in mass casualty attacks and violence, law enforcement must act, not necessarily to arrest, but to intervene.

"Action may not mean making an arrest. Action may mean working with the family, working with mental health professionals, working with others in the community to reduce the risk posed by that individual and prevent them from conducting a mass casualty attack," said Cohen.

Sources say last year police in nearby Chula Vista made contact with one of the suspected shooters, Caleb Vazquez, who was then a juvenile, after someone who knew him raised concerns he was interested in extremist ideology and mass-casualty attacks.

An officer reviewed Vazquez's social media accounts, allegedly finding neo-Nazi rhetoric.

But sources say the concerns did not rise to the level of an arrest and it is unclear whether there was any follow-up.

"The law enforcement organization that receives that information needs to not just determine whether there is an arrestable offense that's taken place, but they need to conduct a threat assessment," said Cohen.

The I-Team recently traveled to US Secret Service headquarters in Washington, D.C., profiling the work of the National Threat Assessment Center whose research is designed to prevent targeted violence like the shooting in San Diego. NTAC trains law enforcement agencies, schools and communities across the country, including in the Chicago area, to identify troubling behaviors and intervene before it's too late.

"These concerning behaviors that are exhibited by these attackers and plotters have been very consistent," said Katie Lord, Supervisory Domestic Security Strategist, NTAC.

Troubling signs like those exhibited by the suspected shooters, interest in mass shootings, neo-Naziism and more should have triggered early intervention, said Cohen. "Law enforcement can no longer afford just to take action solely upon a determination that a crime has been committed in today's threat environment."

The I-Team reached out to the Chula Vista police department. We did not hear back but a spokesperson told ABC News Tuesday in part that the department "extends its deepest condolences to all those affected by this tragedy."

Investigators say they've now seized more than 30 firearms from two homes connected to the teen attackers.