(NBC) — Friday on “Dateline,” when Diane Kyne is found dead in her bedroom, competing stories emerge about which of the most important men in her life may have killed her.

Here’s a preview of Dennis Murphy’s report:

The 9-1-1 operators in Pinellas County Florida are used to dealing with life and death emergencies, but this one was different. Diane Kyne was dead. Her husband and son were both distraught and both making frantic calls.

First Kevin.

KEVIN KYNE: My dad’s trying to kill me. Help me, please. He’s outside of my house, he’s choking me.

9-1-1: OK, calm down so —

KEVIN KYNE: He killed my mom.

9-1-1: Stay on the phone with me.

KEVIN KYNE: I can’t hold on much longer.

And then Bill.

BILL KYNE: My son just killed my wife. He and my wife were arguing and he was choking her.

9-1-1: Where is your son?

BILL KYNE: He-he-he ran out the door.

Two calls from the same location, just minutes apart.

Kevin Kyne and his step-father Bill, each accusing the other of murder.

BILL KYNE: Oh, please.

9-1-1: Sir?

BILL KYNE: Be quick.

Father and son — one falsely accused of an appalling crime.

The other — the real killer — and a devious liar.

Watch “Dateline: True Lies” at 10 p.m. Friday on NBC4.

“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.

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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.