In late December 1989, 11-year-old Collier (Boyle) Landry heard a scream and loud “thumps” coming from his mother, Noreen’s bedroom. The next morning, his father, Dr. John Boyle, told the child his mother had gone on “vacation,” but Collier says he didn’t believe it.

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The police investigation into Noreen Boyle’s disappearance revealed John had a pregnant mistress and a “secret” house in another state. Noreen’s body was found three weeks after she went missing - buried under the basement floor in the new home.

At Boyle’s murder trial, Collier testified against his dad, helping to put him behind bars. 

WATCH: Man Who Testified Against Dad In Mother's Murder Trial Claims, 'It Was Completely Premeditated'

But more than a quarter-century after his guilty verdict, Dr. Boyle continued to insist he was innocent of his wife’s murder.

On Wednesday’s Dr. Phil, Collier talks about what it was like to confront his father in prison, and discusses why he decided to allow his family’s tragedy to become the documentary film, “A Murder in Mansfield.”

In Today’s Takeaway, Dr. Phil explores the “domino effect” of trauma and how it can impact entire families.

Check here to find out where you can watch Wednesday’s episode.

Footage/photos provided by Investigation Discovery. “A Murder in Mansfield" premieres on Investigation Discovery and IDGO at 9 p.m. EST on Saturday, November 17, 2018.

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Man Says He Confronted Dad In Prison After 26 Years Because He Wanted Answers About Mother’s Murder