You Vote: Do you think the murder of Charlie Kirk involved more people than the 1 alleged shooter?

FBI Deputy Director Dan Bongino on Monday revealed that the suspect in Charlie Kirk's assassination displayed "multiple warning signs" before he carried out the shooting.

Officials last week arrested 22-year-old Tyler Robinson for the murder, after a family member reached out to a family friend, who contacted the Washington County Sheriff's Office and said Robinson confessed or implied he committed the shooting.

Bongino and FBI Director Kash Patel shared additional information on Robinson in Fox News interviews, where Patel said DNA evidence places Robinson at the crime scene.

The deputy director said Robinson appeared to have exhibited "multiple warning signs," before the fatal shooting last week, including a recent interest in politics and a discussion with family about Kirk's upcoming appearance in Utah and their dislike for the conservative activist. 

The official said they are looking into whether other people in Robinson's network, including online contacts, knew something about the shooting in advance and failed to notify law enforcement.

"Did they ... hear it and think it was a joke? That is what we're trying to find out now," Bongino questioned. "If there is a larger network here, we will get that out to the public as soon as we can."

Bongino also said the bureau is looking into whether someone on the ground was involved in the shooting, including whether Kirk answering a question about transgender shooters just before he was shot was a signal. 

The deputy director added that the FBI will be looking into whether there was an extended network involved through subpoenas.