This Friday, April 18, 2025, at 9/8c, Dateline NBC presents “A Cool Desert Morning,” a chilling investigation into the mysterious death of Susan Winters, a Nevada attorney whose initial death was ruled a suicide, but her family believed otherwise.

In 2015, Susan Winters was found unresponsive in her Henderson, Nevada home, and her husband, Gregory Brent Dennis, claimed she took her own life by ingesting antifreeze and oxycodone. However, Susan’s family was determined to uncover the truth and launched their own investigation, believing her death was not suicide but murder. After hiring private investigators, the Winters family discovered unsettling details about Dennis’ secret life, leading to a civil lawsuit and, eventually, his arrest.

Dateline correspondent Josh Mankiewicz reports on this gripping case, which reveals the dark secrets of a troubled marriage and a determined family seeking justice. Tune in for this compelling episode, which includes interviews with Susan’s family, detectives, and those involved in the investigation,...