How do we think about him? Is he a sociopath? What is he?

Yeah, I've asked that before and I...

How do I put this so that you can put it on the arrow?

I would put him as a pure evil person.

Previously on Bearbrook.

Through DNA testing, we've determined that this man, this killer, Bob Evans,

is the father of the middle child victim in Alistair, this young brother.

It was fascinating about Lisa, but just still not know who they were and know so much was difficult.

You know if these folks are sharing DNA, then that person has to be a descendant of that common ancestor.

She had said that she did have other siblings, but they had died while they were out camping for meeting,

quote unquote, rass mushrooms.

What do you hear as an investigator when you hear that?

There's more victims.

For 20 years, Diane worked as a 911 call operator.

And in that time, she's taken just about every kind of phone call you could imagine.

I've delivered a baby over the phone and you know, I'm sure I've saved lives.

I've also been the last person that people have talked to before they decided to take their own.

Diane lives in a suburb outside Chicago.

I reached her by Skype a few weeks ago.

We're not using her last name.

I'll explain why in just a second.

You're like your profession is like full of dealing with like really heavy stuff.

...