"48 HOURS" INVESTIGATES TWO UNUSUAL CASES THAT EXPOSE DARK SECRETS, GREED AND TROUBLED RELATIONSHIPS IN A SATURDAY NIGHT DOUBLE FEATURE

"Death on the Hudson" - 9:00 PM, ET/PT

"Grapes of Wrath" - 10:00 PM, ET/PT

Peter Van Sant and 48 HOURS have the latest twist that raised serious questions in the case against Angelika Graswald, who was charged with killing her fiancé, Vincent Viafore, during a kayaking trip, and the stunning resolution that shocked his family, in an updated encore of "Death on The Hudson" to be broadcast Saturday, August 18 (9:00 PM, ET/PT) on the CBS Television Network.

The couple went out for a kayaking trip on the Hudson River in Cornwall, N.Y., in April 2015. Graswald returned from the trip; Viafore didn't. Graswald said that the weather changed while they were on the river and Viafore's kayak capsized. He wasn't wearing a vest. She said he disappeared under the water.

Police maintained that his kayak was missing a plug that allowed water to fill his boat as he desperately tried to return home. Investigators maintained Graswald killed Viafore because she stood to gain hundreds of thousands in insurance payouts and their relationship had soured.

Investigators also said she had made statements that implicated her in the crime. Her defense team argued Viafore's death was an accident, nothing more, and the plug in the kayak that police say led to his drowning was removed long before the incident. Her attorneys said that the size and position of the hole for the plug took in less water than the open well of the kayak did in rough water.

Was Viafore murdered, or was his death a tragic boating accident? After years of claiming she was innocent, Graswald agreed to plead guilty to negligent homicide. But that was just the start of a new, stunning twist in the story of the fateful kayaking trip that continues today.

And at 10:00 PM, Tracy Smith and 48 HOURS investigate a business deal gone wrong in an encore of "Grapes of Wrath," which focuses on an investor in a Napa Valley winery who ponied up $800,000 in cash in an effort to make a fortune in fine wine. What he didn't realize then was he was investing in his own murder.

"He shot me! He's coming after me in his truck," investor Emad Tawfilis shouted to a 911 dispatcher as he tried to outrun Robert Dahl through the California vineyard.

Smith and 48 HOURS investigate the unlikely showdown between Tawfilis and Dahl, which exposes the unusual relationship between Dahl, an entrepreneur drawn to the glamour of the Napa Valley wine scene, and Tawfilis, a wealthy Silicon Valley businessman willing to turn over his nest egg - in cash stuffed in a gym bag - to the entrepreneur with big plans.

"Money is intoxicating ... and when you mix money and wine, I think you get intoxicated to the second or third power," says Lew Perdue, a tech entrepreneur and wine writer.

Dahl and Tawfilis both wanted to be in the lucrative wine business. That didn't work out as planned. The deal wasn't as it seemed and led to mistrust and a lawsuit. What followed was a story about ambition, greed and stunning deception that unraveled in the same fields both men thought would make them richer.

What went wrong between these two millionaires? What led to murder in the vineyard?

48 HOURS: "Death on the Hudson" is produced by Patti Aronofsky, Elena DiFiore and Lourdes Aguiar. Gregory McLaughlin is the producer editor. Ryan Smith and Kathleen O'Connell are the development producers. Linda Martin is the update producer. Nancy Kramer is the executive story editor. Susan Zirinsky is the senior executive producer.

48 HOURS: "Grapes of Wrath" is produced by Chuck Stevenson and Anthony Venditti. Greg Fisher and Michelle Fanucci are the development producers. Linda Martin is the update producer. Grayce Arlotta-Berner, Richard Barber and Jud Johnston are the editors. Linda Martin is the update producer. Peter Schweitzer is the senior producer. Nancy Kramer is the executive story editor. Susan Zirinsky is the senior executive producer.

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