José Díaz-Balart

Serbian police discovered that David had purchased a burner phone with that number.

But the clincher came at this hardware store on the outskirts of Madrid.

Police found that on the day Ana disappeared, a customer bought the same exact paint the man in the helmet used to cover the security camera.

There's a camera right here as he purchases this.

Yes.

But there was a hitch.

According to Spanish law, businesses are only required to hang on to security footage for two weeks, and Ana had by then been missing for much longer.

I'm just struck by the extraordinary luck in this investigation.

The fact that the suspect, when he spray paints the lens, shows for just a nanosecond the brand...

of the paint.

And then this is way past 14 days, and he had the video.

And he had the video.

And for the first time, a clear image of the buyer.

We didn't have any doubt that it was David and that David was the one who bought the spray paint.

I just can't imagine what your reaction was when you open up those files and see this.

What do you say when you see that?

Agent Montilla believed she had enough evidence to arrest David.

And since Ana was an American citizen, David could face charges in the U.S.

Just one problem.

David was back in Serbia.