(NBC News) — Friday, on “Dateline,” after the wife of a college professor who was also a member of a famous oil empire family, Jill Halliburton Su, is found murdered in her South Florida home, her son tells investigators that footage from the home’s security camera could hold the key to finding the killer.

Here is a preview of Dennis Murphy’s report:

It happened on Sept. 8, 2014.

The night before, Justin’s parents returned from a trip to Malaysia. The next morning, his dad shook off his jet lag and headed to his office at the local campus of the University of Florida.

Justin’s mom slept in but was up when Justin left the house around 9:30 that morning.

JUSTIN: My mother was in the living room in her pink robe. And she was reading a book. And I said, “See you when I get home from work.”

Justin also worked part-time at the University of Florida as a professor’s assistant.

Shortly after noon, he got a call from his father.

JUSTIN: And the first thing he asked me was “Are– are you home right now? Like, are you– are you home?” I’m, like, “No. I’m at work.”

The reason for the call: From his office, Justin’s dad had seen something unusual on a remote security camera.

What he saw wasn’t much more than a glimpse — was a live-feed image of a figure in the house.

SU: He walk in from the kitchen — toward the breakfast area, and disappear from the — the view of the camera, and next thing I know is the — I lost my image

He thought the figure might be his son. But If it wasn’t Justin, who was it?

Watch Friday’s “Dateline,” at 9 p.m. on NBC4.

About ‘Dateline’

“Dateline NBC” is the longest-running series in NBC primetime history and is in its 31st season. “Dateline” is anchored by Lester Holt and features correspondents Andrea Canning, Josh Mankiewicz, Natalie Morales, Keith Morrison and Dennis Murphy.

“Dateline” is the #1 Friday newsmagazine and reaches more than 17 million people every week through its broadcast, and millions more through its social media platforms and podcasts.

The stories range from compelling mysteries to powerful documentaries and in-depth investigations. When major news breaks, they go to the scene, putting the pieces together to bring the viewer the full picture. And in every story they tell, they help the real people who lived the events share their journeys with the viewer.