'The Preacher's Wife' airs Friday, November 5th, at 9pm/8c:

After serving time in jail and regaining custody of her children, Mary Winkler, who made headlines in March 2006 for killing her preacher husband and father of three daughters, sits down for an exclusive primetime interview with Dateline correspondent Keith Morrison, this Friday, Nov. 5. For the special two-hour report, Winkler speaks out about her husband's dark side, and reveals what drove her to end his life to protect hers and the lives of their daughters.

In March 2006, Matthew Winkler, known by his congregation as a pious preacher and loving father and husband, was found dead in his own bed in the small town of Selmer, Tennessee. Police searched for his wife and children for days, finally tracking them down in an Alabama town over 400 miles away. After she confessed to killing him, the trial of Mary Winkler appeared to be case closed, until she finally spoke up and revealed to the court the intensely private secrets of her husband's dark side.

In the interview with Morrison, Winkler explains the inner struggle she faced as a loyal wife who allegedly suffered severe mental and physical abuse at the hand of her husband. She says she is telling her story now to advise all the women who suffer the same type of abuse. "Ask for help….Know that someone will believe you, someone will help you. And you're not alone. I'm not leading by example. But I am leading out of regret."

Watch a teaser for 'The Preacher's Wife' below: