(NBC News) — On Friday’s “Dateline,” after a violent home invasion rocks a small town, police and the FBI launch a complex investigation spanning three states.

Here is a preview of Andrea Canning’s report:

Police in Saco, Maine, had a strange, violent crime on their hands: A home invasion with a shooter at large and a victim in intensive care.

As Rachel lay in the ICU, police in Maine needed to get in touch with her husband, Gregg. They called their counterparts in Londonderry, New Hampshire, 90 miles away. Sergeant Nick Pinardi is with the police department in Londonderry.

SGT. NICK PINARDI: We were working a midnight shift. It was me and a couple other officers.

Saco police wanted him to go break the news to Gregg in person.

SGT. NICK PINARDI: So, I simply went over and told him, “Your wife was shot, in Maine.” At that point, Mr. Owens said he thought he was having a heart attack. So, um, the officers helped him to the ground, sat him down.

It turned out, it wasn’t a heart attack, he’d apparently gone into shock. Gregg was eager to go see his wife, but first, he went down to the police station, full of questions about her condition.

GREGG: Status of my wife?

POLICE: Yeah, uh, she’s at the hospital right now.

GREGG: She’s alive?

POLICE: She’s alive.

GREGG: Prognosis?

POLICE: We’re not sure right now– she’s still in surgery. But she’s, you know, she’s still alive right now.

GREGG: Any idea what happened?

POLICE: Uh, we — Maine’s trying to get some information, they’re investigating it on their side.

Gregg explained that his wife had gone up to Maine for a few days to stay with friends. He said she had been struggling with her health recently and needed a getaway.

POLICE: What is the issue?

GREGG: Uh, they’re saying that it’s early– it’s an early-onset dementia.

Watch “Dateline: The Intruder” Friday on NBC4 at 10 p.m.

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.