Shivangi Sinha
When Gregory Brent Dennis called 911 in January 2015 to report his wife, Susan Winters, unconscious, investigators initially accepted his story and ruled her death a suicide. However, Susan’s family remained convinced that foul play was involved and hired private detectives to dig deeper. Their work uncovered inconsistencies that led prosecutors to reopen the case and ultimately charge her husband with murder. NBC’s ‘Dateline’ episode ‘A Cool Desert Morning’ chronicles the twists in the investigation and how Brent Dennis was finally convicted years after Susan’s death.
Gregory Brent Dennis Alleged His Wife Tried to Kill Herself After an Argument
Gregory Brent Dennis first crossed paths with Susan Winters while attending Blanchard High School in Blanchard, Oklahoma. She was four years younger and they had no romantic connection at the time. He later pursued a career in psychology and entered into a marriage that eventually ended in divorce. It was only later, through a mutual friend, that he reconnected with Susan. The two quickly developed a strong connection, and their relationship blossomed into love. In 1995, they tied the knot and began their married life together in Henderson, Nevada.
In October 1999, Dennis and Susan welcomed their first daughter, Avis Elle, and in April 2002, they were blessed with another daughter, Anna Danielle. By all outward appearances, their life seemed stable and content. However, everything changed on the morning of January 3, 2015. Brent called 911, claiming that Susan had tried to kill herself and was unconscious. Emergency responders rushed her to the hospital, but she passed away not long after. Dennis alleged that she lived with severe anxiety and depression, even claiming she had tried to take her life in 2012. His statements prompted further questions from investigators about the circumstances surrounding that day.
Dennis claimed that he and Susan had gotten into an argument the night before her death, during which she had been drinking while on her prescribed medications. According to him, their daughters had chosen to leave for a shopping center the next day to avoid the tension at home, and he had gone to pick them up. When he returned, he alleged that he had found Susan unconscious. He also told police that she had been searching online for ways to harm herself using antifreeze. Investigators did find empty antifreeze bottles in the garage, and the substance was noted in her autopsy report. Though the case was initially ruled a suicide and closed, Susan’s family, particularly her parents, Danny and Avis Winters, refused to accept that explanation and continued pushing for answers.
Efforts by Susan’s Family Yielded Overwhelming Evidence Against Gregory Brent Dennis
In 2016, Susan Winters’ family filed a civil lawsuit against Gregory Brent Dennis for her wrongful death, hoping it would allow them to subpoena more evidence and uncover the full truth. Through this legal action, troubling inconsistencies in his version of events began to surface. The family questioned the plausibility of suicide by antifreeze, pointing out that it leads to a slow and painful death. They also found their former son-in-law’s behavior suspicious. He reportedly began discarding his wife’s belongings just days after her death. Investigations by private detectives and a criminal attorney revealed that Dennis had allegedly been battling a drug dependency at the time.
There were also several financial red flags that raised suspicions about Dennis’s intentions. Just days after Susan’s death, he deposited a $180,000 check from her account into a joint account they shared. In addition, he was the sole beneficiary of a $1 million life insurance policy and wasted no time in contacting the insurance company on the very first business day after her passing. He had also sold her shares in her family’s business, which were valued at approximately $700,000. Following the civil suit, Dennis’ phone records were subpoenaed, revealing even more evidence that cast doubt on his earlier claims.
On the morning of Susan’s death, evidence revealed that Dennis hadn’t stayed home as he had claimed. Instead, he had driven to The Orleans casino in Las Vegas to meet his drug dealer. This revelation, combined with other evidence, prompted authorities to reopen the criminal case. A search warrant was issued for his home and phone, uncovering audio recordings of intense arguments between the couple, which indicated deep marital discord. Susan’s toxicology report also showed the presence of oxycodone along with antifreeze. Prosecutors later argued that Dennis initially tried to poison Susan with antifreeze, and when that failed, he allegedly gave her a fatal dose of oxycodone obtained during his early morning meeting.
Gregory Brent Dennis is Behind Bars Today
In February 2017, Gregory Brent Dennis was arrested and charged with first-degree murder in connection with the death of his wife, Susan Winters. He denied all allegations, and during the legal proceedings and when his elder daughter was deposed, she also defended him. The case dragged on for several years, filled with legal arguments and delays. Finally, in January 2022, Dennis entered an Alford plea, which means that while he did not admit guilt, he acknowledged that prosecutors had enough evidence to likely secure a conviction at trial.
In May 2022, he was sentenced to serve between three to ten years in prison. The following year, the civil case filed by Susan’s family was also concluded, with the court ordering Dennis to pay over $1 million in damages to her loved ones. Now 63, Dennis is currently incarcerated at the Three Lakes Valley Conservation Camp in Indian Springs, Nevada. Though he was eligible for a parole hearing in March 2025, he remains behind bars.
Read More: Susan Winters Murder Details and Investigation Timeline
