LAS VEGAS (KLAS) — A former psychologist accused of killing his wife with antifreeze and opioids agreed Tuesday to a lesser charge of voluntary manslaughter.

Dr. Gregory “Brent” Dennis, 59, had faced homicide charges in a legal battle spanning years since his wife’s 2015 death. He entered an Alford plea on Tuesday, admitting that prosecutors had enough evidence to convict him in the case, but admitting no guilt.

He agreed to serve 3-10 years in prison.

When Susan Winters, an attorney, died in Jan. 2015, there was enough antifreeze in her system to kill her twice over, officials said.

After the 8 News Now I-Team ran several stories on Winters’ death, Henderson police reopened its examination of the case.

Winters had a lethal amount of oxycodone in her system, and a deadly dose of a chemical from antifreeze. Alone, either one would have killed her.

The death was originally ruled a suicide but that changed after the Winters family hired its own private investigators.

Two bottles of outdated antifreeze as shown in court. (KLAS)

In February 2017, the board suspended Dennis’ license. It was later reinstated with strict monitoring. Dennis’ license expired in 2020.

He initially told Henderson police he didn’t know there was any antifreeze in the house but hours later showed them some bottles in the garage.

Police took photos but the bottles were not taken into evidence and were gone by the time murder charges were filed a year later.

According to the initial arrest report, Dennis told first responders he suspected Susan had ingested antifreeze because he’d found a page of Internet searches, supposedly made by Susan the night before, seeking information about antifreeze poisoning.

Police took a photo of the search list. But months later, investigators learned the last of the searches was done at 5:15 a.m., a time when Winters was out cold and nearly dead. Ninety minutes after the last computer search, Dennis called 911.

A trial in the case had been scheduled earlier this year but was delayed due to the COVID-19 pandemic.

The maximum sentence for voluntary manslaughter is 10 years. A judge will formally sentence Dennis on May 10.