Who was Susan Winters and what happened to her? Death by antifreeze explored ahead of NBC Dateline episode

Susan Winters, a 48-year-old lawyer, was a married mother-of-two residing in Henderson, Nevada, at the time of her death.

She was found unconscious during the early morning hours of January 3, 2015, at the home she shared with psychologist husband Gregory Brent Dennis and their two daughters. Winters was later pronounced dead at a local hospital.

Winters' case was initially ruled to be a suicide after her husband told authorities she was depressed, often made suicide threats, and may have consumed prescribed medication with antifreeze, which killed her. However, a thorough investigation revealed that there was more to the story.

On Friday, October 7, 2022, Dateline will have Josh Mankiewicz report on Susan Winters' murder case in an upcoming episode titled A Cool Desert Morning. The episode is scheduled to air at 9 pm ET on NBC.

The article discusses more about Susan Winters and her alleged murder by her husband.

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Susan Winters played softball and practiced law during the 80s and 90s in Blanchard Oklahoma

Sources state that Susan Winters was a star softball player and even participated for the 1983 Class 3A state softball champions, the Blanchard Lions. The former Blanchard, Oklahoma City resident graduated from Oklahoma University with a degree in political science. She also studied law at the same university.

Winters practiced law in Oklahoma City for a while before moving to Nevada in the 90s, working at the Clark County District Attorney's office. Eventually, she went on to work as a part-time judge.

In August 1995, Susan Winters married husband Gregory Brent Dennis and by Spring 2002, they had two daughters. She adored her daughters and was an enthusiastic reader, runner, and Elvis Presley fan. However, her marriage to Dennis wasn't an easy one and the couple briefly separated for a few months in 2013.

During the initial stages of the investigation into her death, the Clark County Coroner's Office determined that Winters had killed herself using a lethal combination of prescription opioids and antifreeze.

However, investigators later said that Dennis gave his wife a deadly concoction of oxycodone and antifreeze because he was having financial troubles. They also found that Winters had reportedly confronted her husband about doing drugs and threatened to report him to the police and the state licensing board.

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Authorities believed Susan Winters' husband Gregory Brent Dennis poisoned her for financial gains

Susan's parents believed that Dennis killed her to gain over $1 million in life insurance and inheritance money. They also hired a private investigator to look into the matter.

Her parents believed Dennis had a serious drug problem and was using their money to support his habits. They said that Gregory was hoping for a large payout to continue pursuing his habits. He allegedly claimed the life insurance money a day after Susan's death.

Police detained Dennis on allegations of open murder with a deadly weapon nearly two years later in February 2017. He was reportedly found in possession of three painkiller tablets in his right front trousers pocket at the time of his arrest. It was alleged that he acquired prescribed opioids from his own patients. Officials then changed the cause of Susan Winters' death from suicide to undetermined.

Dennis was charged by the prosecution with looking up online the approximate time it takes for ethylene glycol, the deadly component of antifreeze, to kill a person. He was officially indicted for the crimes on October 5, 2017. Prosecutors later also mentioned "a theory of manual suffocation" in Winters' murder case.

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NBC Dateline airs on Friday, October 7, 2022 at 9 pm ET.