(NBC) — On “Dateline” Friday, two young women are shot and left for dead on a beach in Texas, Mollie Olgin, 19, was pronounced dead at the scene and 18-year-old Mary Kristene Chapa, miraculously survived, determined to find the women’s attacker.

When a young man is eventually convicted, the long road to justice seems to be complete until a stunning twist.

Here’s a preview of Josh Mankiewicz’s report:

As dawn gave way to morning on that June day in 2012, news that two young women had been shot in one of the parks began to slowly spread throughout San Patricio county. Brittany Selby tried to call both Kristene and Mollie.

BRITTANY SELBY: Neither one of them is picking up. So that’s when I started to get worried.

Kristene’s mother, Grace, was worried too. Her husband Larry was out of town, and she had been pacing the floor all night, ever since she discovered Kristene hadn’t come home.

JOSH MANKIEWICZ: By now, how many times have you called your daughter?

GRACE CHAPA: I would say about four or five times I called her. I even told her, “I’m gonna call the police if you don’t call me right now.”

Eventually, grace -did- call the police and that’s when worry turned to panic.

Watch Friday’s “Dateline: The Overlook” on NBC4 at 10 p.m., Dec. 17.

About ‘Dateline’

“Dateline NBC” is the longest-running series in NBC primetime history and is in its 30th 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.