Ina Kenoyer Poisoned Her Boyfriend Over a Fake Inheritance

Ina Thea Kenoyer is a Minot, North Dakota woman who poisoned her longtime boyfriend, Steven Edward Riley Jr., with antifreeze in September 2023, killing him over a $30 million inheritance that turned out to be an online scam. She pleaded guilty to murder and was sentenced in October 2024 to 25 years in prison.¹

The Fake Inheritance Behind the Killing

Riley, 51, had received an email from someone claiming to be a lawyer representing a distant relative’s estate and telling him he stood to inherit more than $30 million. He believed it. He arranged to meet the supposed attorney at Minot International Airport on September 3, 2023, to sign paperwork and finalize the transaction. No one showed up.²

Investigators later determined there was no inheritance and no long-lost relative. Minot Police Chief John Klug told reporters, “We have nothing to indicate that there was a long-lost relative.”³ The person who had contacted Riley was never identified, and no one was charged with the fraud itself.⁴

Both Riley and Kenoyer thought the money was real. Riley told people he planned to buy land, support his children, and open an auto shop. He also planned to end his roughly ten-year relationship with Kenoyer once the money arrived, and friends told investigators she knew that.¹

How She Poisoned Steven Riley

On September 3, 2023, the same day Riley expected to collect the inheritance, Kenoyer laced his sweet tea with ethylene glycol, the primary toxic ingredient in antifreeze. Ethylene glycol has a sweet taste, which hid it in the drink. Kenoyer later admitted she had been making Riley sweet tea throughout the day.¹

Riley’s health fell apart that evening. As he got sicker, Kenoyer told people he had heat stroke, refused to let others get him medical help, and falsely told a friend that Riley had visited a walk-in clinic. A witness, Theresa Akin, saw Kenoyer throwing away Riley’s belongings that day and said Kenoyer was angry because Riley “was going to get his inheritance and leave her.”⁵

By September 5, Riley was unconscious. He was taken to a Minot emergency room, then airlifted to a hospital in Bismarck, where he died that day without regaining consciousness.¹

How Investigators Caught Her

Riley’s friends and family contacted the Minot Police Department with suspicions after his death. Several witnesses said Kenoyer had talked in the past about poisoning Riley with antifreeze. Others said she had told people at the hospital that Riley had been poisoned with antifreeze before any doctor or lab result had identified a cause of death.⁵

An autopsy confirmed the cause of death as ethylene glycol poisoning, with toxic levels in Riley’s blood. Hospital tests taken when he was admitted showed no alcohol in his system, contradicting Kenoyer’s earlier claim that he had been drinking heavily.⁵

A search of the couple’s home turned up a Coors Light bottle and a plastic mug that both contained traces of suspected antifreeze, along with an old Windex bottle filled with bright green liquid. Investigators also reported finding gallon bottles of antifreeze in the garage and traces of antifreeze in open beer bottles and drinking glasses around the home.⁶

Her Motive

Kenoyer believed she was entitled to a share of the expected $30 million because she considered herself Riley’s common-law wife after their long relationship. North Dakota does not recognize common-law marriage. When investigators told her she would have no legal claim to any inheritance, she became “angry and upset,” according to court documents.¹

Prosecutors concluded that Kenoyer poisoned Riley on the very day he expected to collect, planning to then claim a share as his surviving partner. A neighbor, Rebecca Mello, said Kenoyer “was very resentful of the thought of him having that money, leaving her, and her having nothing.”⁶ Witnesses also said Kenoyer tried to sell Riley’s vehicle while he was dying in the hospital.¹

Charges, Guilty Plea, and Sentence

Kenoyer was arrested on October 30, 2023, and charged with Class AA felony murder. She was held at the Ward County Detention Center on a $1 million bond.⁴ At her December 7, 2023 arraignment, she waived a preliminary hearing and pleaded not guilty.⁷

On May 29, 2024, at a pretrial conference, Kenoyer changed her plea to guilty. Under a plea agreement, she pleaded guilty to murder with extreme indifference to human life.⁸ Ward County State’s Attorney Roza Larson prosecuted the case; Tyler Morrow represented Kenoyer.¹

On October 16, 2024, North Central District Court Judge Richard Hagar sentenced Kenoyer to 50 years in prison with 25 years to serve, the remaining 25 years suspended, followed by 10 years of supervised probation. She was ordered to pay $3,455 in restitution to Riley’s family. When the judge asked if she wanted to make a statement, she said nothing.¹

Riley’s sister, Stephanie Gonzalez, addressed Kenoyer at sentencing. “You stole more than a human life. You stole a son from his mother and stepfather. You stole a father from five sons, a brother from two sisters, an uncle from 12 nieces and nephews, and a great uncle to eight, and many friends,” she said. She added, “Lucky for you, the Department of Corrections doesn’t serve antifreeze in their iced tea.”⁹

Where She Is Now

Kenoyer is serving her sentence at the Dakota Women’s Correctional Facility and Rehabilitation Center, with an estimated release date of January 27, 2045. No appeals have been publicly reported.⁶

1
Minot Daily News. Kenoyer Gets 25 Years for Poisoning Death
2
New York Post. Steven Edward Riley Jr. Was Poisoned Over Inheritance Scam
3
KFYR-TV. Questions Raised About Inheritance in Minot Poisoning Case
4
KX Net. Minot Woman Charged With Poisoning Boyfriend
5
CBS News. North Dakota Poison Murder: Ina Kenoyer Allegedly Killed Boyfriend Steven Riley
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Oxygen. Why Did Ina Kenoyer Kill Steven Riley Case Explained
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KFYR-TV. Not Guilty Plea Entered in Minot Poisoning Case
8
KX Net. Minot Woman Changes Plea to Guilty for Fatally Poisoning Boyfriend
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KFYR-TV. Kenoyer to Serve 25 Years in Minot Poisoning Death