This is Hidden Killers with Tony Bruske.

We're going to be looking into one of the most overlooked and emotionally complicated layers of the Brian

Coburger case, his family. And this is not a piece to expose his family or cause, you know, tout blame on his family.

I don't think they have anything to do with this whatsoever. I think they are very much victims

in this as well. The people who just days before the world knew his name, they were sharing

holiday meals with him. The same people who may now be walking into a courtroom,

not just to sit behind him in support, but to testify against him, not out of malice, but because

they might have seen and heard things no one else did. Now imagine being a parent or sibling

in that position. One minute you're watching Wheel of Fortune with your kid,

the next, you're on a subpoena list. That's not exactly the Christmas vibe anyone's going for.

Joining us is someone who knows exactly what it means to analyze behavior when emotions are running

high, retired FBI special agent and chief of the counterintelligence behavioral analysis program, Robin, when you hear that prosecutors may be calling Coburger's own father or sister

to testify, what immediately jumps out to you as a behavioral expert? And how does a situation

like this where familial loyalty crashes into legal

obligation tend to play out inside a house room or more or less a courtroom?

Sensitive soft touch, which is always going to be key and critical, because here's a father

and siblings and family members that you know it's hard to

get over this is your son this is your brother this is your baby boy i mean i always use that term

thing in my own kids yeah i think you know the best way so here if i was doing this and i think

what they're going to do here as well is they're not going to ask an opinion of him.

They're not going to go down that road of subjective observation.

I think they're going to most likely stick with observations of life arcs, behaviors.

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