Dateline Susan Winters’ Parents, Avis And Dan, Seek Justice Amid Suspicion Of Fatal Dose Of Antifreeze And Oxycodone

Henderson, Nevada: Susan Winters, a 48-year-old attorney, lost her life on January 3, 2015, and her husband, Dr. Gregory “Brent” Dennis, claimed she committed suicide using antifreeze and opioids.

Although the initial investigations suggested suicide, her parents never believed it and hired private investigators who put the case in a stunning new light.

Highlights

• Susan Winters’ initial investigations suggested suicide, but her parents didn’t believe it and hired private investigators.
• She was only 48 years old at the time of her tragic demise at her home in Henderson, Nevada, on January 3, 2015.
• Brent was liable for Susan’s death, and a civil court ordered him to pay the Winters family over $1 million.

Susan was unresponsive at her home with high levels of oxycodone and ethylene glycol in her system, and the circumstances surrounding her death led authorities to classify it as a suicide.

Her husband, a psychologist, believed his wife searched online information on antifreeze poisoning and ingested it.

Dennis informed the authorities that Susan struggled with depression and spoke about wanting to end her life. Their two daughters supported Dennis’ claims and stated Susan was in emotional distress.

Previously, Susan tried to take her life during their brief split in 2012, which made it plausible that she had committed suicide.

However, private investigations raised questions about whether her husband was responsible for his poisoning.

Susan Winters’ Parents Never Believed That Their Daughter Committed Suicide

Susan Winters, the daughter of Avis and Dan, was born and raised in Oklahoma. Her parents, brother, and sister-in-law launched their investigation and hired a team of private investigators.

Her parents and family members only wanted justice for her, and that was the only thing that kept them going.

 

On January 3, 1015, Susan was rushed to the local hospital. Although the emergency responders were able to restore a pulse, she had swelling around her brain, and the prognosis wasn’t good.

Later, she passed away before her parents made it to the hospital.  Her parents didn’t believe that she took her own life cause a week before her death, she was happy and planned for the new year ahead.

Their suspicions grew when Brent laid out Susan’s belongings just five days after her demise and told her friends they could take whatever they wanted.

Avis remarked Brent treated her like trash that he could discard at will.

Afterward, Susan’s parents hired a private investigation firm, which kept Brent under surveillance and quickly learned he was leading a secret double life.

They learned he frequently visited The Orleans casino in Las Vegas, where he often met with a man previously convicted of cocaine-related offenses.

Later, they hired criminal defense attorney Tony Sgro and used their extensive financial resources from over 100 restaurant franchises to fund the investigation.

They discovered that Brent deposited a $180,000 check from her account into their joint account days after her death. Susan also had a $1 million life insurance policy listing him as a beneficiary, and he called to claim it immediately after her death.

Moreover, Brent gained control of her shares in her family’s restaurant business, which the Winters bought back for approximately $700,000, as they wanted him gone.

Susan’s parents assumed Brent had a financial motive for her death and sued him for wrongful death. He admitted to drug use and claimed she threatened to turn him in but dismissed the threats.

Clark County Prosecutor Marc DiGiacomo reopened the case in 2016 and found evidence of a dysfunctional relationship between Susan and Brent. He theorized Brent poisoned her with antifreeze and later gave her a fatal dose of oxycodone.

Afterward, Brent was arrested in 2017 and eventually agreed to enter an Alford plea to voluntary manslaughter, receiving a 3-10-year sentence. In 2023, a civil court found him liable for death and ordered him to pay the Winters family over $1 million.

Despite this, the Winters family feels justice is still lacking. 

For me to think about my daughter laying there, going through that with the antifreeze, oxycodone, whatever else he put in her body, there ought to be a special place in hell for him, and I hope he goes there.

Susan Winters Had a Crush on Gregory Brent Dennis During High School

Susan Winters and Gregory Brent were both into athletics. She excelled in track, basketball, and softball, whereas he was a high school quarterback.

She was a competitive athlete who wasn’t ever satisfied until she gave her best in the field.

 

Brent was the school’s handsome young athlete, and every girl, including Susan, had a crush on him. She was head over heels for him.

However, due to their four-year age gap, they never got to be together during high school. 

They went their separate ways; Susan got her law degree in Henderson, and Brent became a psychologist in San Diego. 

Moreover, they were married to different individuals, but once they divorced, Susan’s sister-in-law played matchmaker, and they reconnected. 

Susan and Brent married in 1995 and settled in Henderson. Later, the married couple welcomed two daughters.

Unfortunately, their life took a tragic turn when Brent called 911 to report his wife wasn’t breathing on January 3, 1015.

Additional Information

• Brent’s behavior after the death of Susan caused chaos within their extended family.
• He insisted that he had been home all night asleep next to his wife, but phone records showed he went to The Orleans hotel to meet up with his drug dealer.