CAN A PERSONAL FITNESS DEVICE TRACKING STEPS AND SLEEP HABITS SAVE A MAN FROM A LIFE IN PRISON?

"48 Hours" Investigates in "The Fitbit Alibi"

Saturday, March 24, 10:00 PM, ET/PT

Can a personal fitness device that tracks steps, exercise and sleep habits save a man from being charged with murder and facing a life in prison?

Erin Moriarty and 48 HOURS investigate a groundbreaking murder case that was solved using 21st century technology in "The Fitbit Alibi" to be broadcast Saturday, March 24 (10:00 PM, ET/PT) on the CBS Television Network.

It's a murder case that shook a community and one that hinges on another technology: Google Dashboard, a tool that many people don't even know they have. But could it convict a killer?

Nicole Vander Heyden went out with friends for a night on the town in Green Bay, Wisc., on May 20, 2016. She never made it home. A day later, she was found dead in a field, having been beaten and strangled to death.

The murder left her friends and family shaken, and the community wondered how it could happen. At the time, Vander Heyden was living with her boyfriend, Doug Detrie, and their 6-month-old son. Detrie was interviewed by sheriff's deputies and quickly became the prime suspect when blood was found on the floor of their garage and in Vander Heyden's car.

"For us, it's adding up," says Detective Sgt. Brian Slinger, of the Brown County Sheriff's Department. "Okay, this is our guy."

Investigators also wondered why Detrie waited hours before reporting her missing. "It doesn't seem like a guy who's particularly worried about his girlfriend, the mother of his child, does it?" Slinger says.

Detrie was wearing a Fitbit device when he was interviewed and when he was arrested. Data recorded about his activities during the window of time Vander Heyden was murdered told a very different story - one that cleared him. He was released 18 days after his arrest.

Over the next several months, Nicole's clothing and items at the murder scene were processed for DNA. That would lead investigators in yet another direction - and to another man.

"Nobody knew who he was," says Kate Briquelet, a writer for the Daily Beast and a native Wisconsinite. "He had no connection to Nikki, no connection to Doug, no connection to any of their friends. I mean, he was literally a mystery man."

What role did the Fitbit play in the case, and how did other technology come into play for the investigators? Moriarty and 48 HOURS report the story through interviews with Vander Heyden's friends and family, investigators, the farmer who found her body, Briquelet and others.

48 HOURS: "The Fitbit Alibi" is produced by Resa Matthews, Mary Ann Rotondi, Marc Goldbaum and Stephanie Slifer. Anthony Batson is the senior broadcast producer. Nancy Kramer is the executive story editor. Susan Zirinsky is the senior executive producer.

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