(NBC) — On Friday’s “Dateline,” after an apparent brazen home invasion during the holiday season in a quiet Connecticut community leaves Connie Dabate dead, investigators discover a silent witness that cracks the case wide open.

Here is a preview of Andrea Canning’s report:

PEGGY: “I came to the sink. And I look over, and I’m like, ‘Holy cow, there’s a state trooper with his rifle drawn on the house.'”

Peggy immediately called Connie, but she didn’t pick up. So, Peggy tried Darlene.

PEGGY: “And asked her if she knew what was going on and had she heard from Connie.”

DARLENE: “And she said there was a — first responder car and a sheriff at Connie’s house. And he was outside the car with his rifle.”

ANDREA CANNING: “That’s really scary.”

DARLENE: “It was like, ‘What?'”

PEGGY: “Before we can, say another sentence — this entire street was full of — state troopers. The driveway had about 1,000 of ’em comin’ up.”

The massive police presence was in response to an alarm triggered at the house Connie shared with her husband, 39-year-old Rick Dabate, and their two children.

That, and a cryptic 911 call.

OPERATOR: “9-1-1 — hello?”

CALLER: “Need help.”

“Dateline” is all new Friday on NBC4 at 8 p.m. CT.

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.