Lester Holt

As I understand it, Wendy Adelson wanted to take the children with her and move closer to her family in South Florida.

Was that the question?

That was the initial question.

And family law court said you cannot do that.

If the children are here in a stable environment and the father can participate fully with the raising of the children, the law prefers that and should.

That motion was denied.

Wendy stayed in Tallahassee with the boys as the court required, eight hours away from her parents' home in South Florida.

Her divorce from Dan became final in 2013.

But the custody arrangement remained a sore point on both sides.

50-50 sharing arrangement with the kids.

Yes, absolutely.

And he availed himself of every second.

And quite frankly, you know, wanted some time that maybe she found offensive.

Offensive enough to kill her ex-husband?

Now police were about to talk to Wendy, who would be remarkably forthcoming about their bitter divorce and a whole lot more.

Setting the stage for a painstaking march toward justice that would rip apart two families.

I'm sitting there thinking, these people are the ones that killed my son.

The investigation into the death of Florida law professor Dan Markell was just hours old when his ex-wife Wendy Adelson first spoke to police.

Through tears, Wendy told the detective she'd been at her home that day having her TV repaired five miles from the crime scene.

After Wendy got control of her emotions, she phoned her mom, Donna.