We're back with episode three of the interrogation tapes, a special limited run series produced

by ABC News Studios in partnership with 2020.

I'm Deborah Roberts co-anchor of 2020.

In today's episode, The Devil in Disguise,

we follow an investigation into the shocking murders of a pregnant mother and her two young children.

Here, what made detectives suspicious in the interrogation room. Facebook was central to Shannan's life, hundreds of posts and videos. It was as if every minute of every day was

documented and shared openly with the public.

Chris and I are sitting here waiting to afford our flights to Miami.

If you guys have an amazing day, bye, see my hat, I loved it.

So I'm going to be your personal last name. I'm going to be your personal last name. I'm going to give you your personal last name?

I'm Chris Watts.

Would you like to study your life in the kids?

If you're out there, just come back.

I need to see everybody again.

This house is not complete.

Just tell me exactly what you remember and I'll say things about where we can go.

So many people that step into the box with the cops, they think they're going to talk their way out of it.

What are you saying to ask me? I'm going to bring out flyers regarding the missing woman in the neighborhood.

You don't know, I haven't seen him around the neighborhood, anything like that. When you see a case like this where you have a fantastic family,

kids are happy, you're always wondering,

what could possibly happen to force someone

to commit such a heinous act.

...