(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.