(NBC) — Tonight on “Dateline: The Secret Keepers,” Keith Morrison reports on the devious plot behind a 59-year-old father’s murder. When Randy Baker is found dead in his home, his family assumes that it’s related to his ongoing health issues. Once the coroner reveals that Randy didn’t die of natural causes, his family is left to wonder if one of their own is behind his mysterious death.

Here is a preview of Morrison’s report:

Betty Winick’s father had a very bad heart. She knew she could lose him — soon. Thought she was ready — but she wasn’t — not at all. Grief like a sledgehammer. She had to tell her mother, Dori, about her father’s death. It wasn’t easy. Dori and Randy had divorced years before but she still loved him.

Dori Baker: I could tell she’s been cryin’. I said, “Betty’s what’s wrong?” and she goes, “Dad’s gone.” and I said, “No, no.” and she goes, “Mom, they found him. They found him this mornin’. But I said, “Betty, something’s wrong. Something’s wrong, something’s wrong.”

Thing is, back at the house that morning, officer Medhurst was thinking the very same thing —especially after Kelly told him the Pontiac was missing. Along with his keys and his wallet.

Two days later, Medhurst got the news: during the autopsy, the medical examiner had taken a closer look — scraped the blood away from Randy’s head and shoulder — and what do you know?

The mystery behind Randy’s death revealed tonight on “Dateline” at 10 p.m. on NBC4, followed by NBC4 at 11.