Deborah Roberts

Once the detective got there, we were asked to leave the residence.

They were up in tape around our house and walking around outside.

So obviously, it had turned into a crime scene at that point.

But we still had no idea what had happened to her.

What had happened?

Emma Walker was killed by a gunshot wound to the head from somebody shooting into the house from outside.

Those two bullets fired through the walls of her bedroom, one striking Emma behind her left ear, the second into the pillow by her head.

You know, to hit a target that you can't see, you would have had to know exactly where Emma's head was going to be.

That realization, I think, is a stunning and chilling one.

You talked to her parents.

Did you ask them if they thought there was somebody who could be out to hurt her?

We spoke to the family.

We spoke to her friends.

And everybody kept giving us the name Riley Gall because of their relationship, because they had seen the way that Riley had treated her, the way he had talked to her.

The Knox County Sheriff's Office goes to talk with Riley, and he's distraught.

Riley goes to social media, posting, Rest easy now, sweetheart.

I love you forever and always.

Riley seems devastated, but he doesn't go to the vigil.

That is held for Emma.

You know, he justifies his absence at this vigil as he's just too broken to attend.