5 chilling details about Ina Kenoyer's crime

In September 2023, Ina Kenoyer, a 47-year-old Minot, North Dakota, woman, poisoned her boyfriend, Steven Riley Jr., with antifreeze, believing he would inherit $30 million. An autopsy revealed ethylene glycol in his system, leading to her arrest for murder in a shocking case of greed.

The whole case will be featured in Oxygen True Crime’s Snapped, Season 35, Episode 14, airing on July 13, 2025, at 6:00 PM ET. The episode explores Kenoyer’s motive, the investigation’s breakthroughs, and the devastating impact on Riley’s family.

The documentary details Kenoyer’s life, her false belief in a common-law marriage, and the evidence that led to her conviction. It includes interviews with Riley’s family, friends, and authorities, exposing the chilling deception behind the crime.

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5 Key details about Ina Kenoyer’s crime

1) Ina poisoned Steven Riley with antifreeze

(Image via Unsplash/@Robert Laursoo)

On September 5, 2023, Steven Riley Jr., a 51-year-old from Minot, died at the Bismarck hospital after being found unresponsive at his home. His girlfriend, Ina Kenoyer, had called 911, claiming he was experiencing heat stroke. While his death initially appeared to be from natural causes, an autopsy later revealed he had been poisoned with ethylene glycol, a toxic substance found in antifreeze, as per Fox News.

Kenoyer admitted to spiking Riley’s sweet tea with antifreeze, believing he would inherit $30 million from an estate, as per Oxygen. She thought she would claim the fortune as his common-law wife. The couple had lived together for years, sharing a home and vehicles.

Riley suffered seizures and died within hours of ingestion. The deliberate use of a household poison highlighted Kenoyer’s calculated intent, shocking the tight-knit Minot community.

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2) Ina Kenoyer believed in a nonexistent $30 million inheritance

(Image via Unsplash/@Alexander Schimmeck)

Ina Kenoyer’s motive stemmed from a false belief that Steven Riley Jr. was set to inherit $30 million from an estate. A friend of Riley’s, posing as an attorney, misled Kenoyer about the inheritance, as per InForum. She thought poisoning him would secure her the fortune, believing North Dakota recognized her as Riley’s common-law wife, as per Oxygen.

However, North Dakota does not legally recognize common-law marriages, nullifying her claim, as per InForum. Kenoyer had discussed the supposed wealth with friends, expressing excitement about the money. The inheritance was entirely fabricated, and no such estate existed, as confirmed by investigators, as per Valley News Live. This delusion drove Kenoyer to murder, revealing her greed and gullibility in a tragic deception.

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3) She tried to cover up the crime with lies

(Image via Unsplash/@David von Diemar)

After Steven Riley Jr.’s death on September 5, 2023, Ina Kenoyer claimed he was unresponsive and had been drinking heavily throughout the day. She told authorities he appeared to be suffering from heat-related illness, which initially led to suspicions of natural causes, as per CBS News.

Investigators found a bottle of antifreeze in their home, and lab tests confirmed ethylene glycol in Riley’s blood, contradicting her story, as per Oxygen. Kenoyer’s attempts to mislead authorities by cleaning the scene and fabricating Riley’s condition delayed the investigation but ultimately unraveled when forensic evidence exposed her lies.

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4) Forensic evidence exposed the poisoning

(Image via Unsplash/@Denise Chan)

The investigation into Steven Riley’s death turned on forensic evidence. After Ina Kenoyer’s 911 call, Minot police initially suspected alcohol poisoning, but an autopsy on September 6, 2023, revealed ethylene glycol in Riley’s system, a lethal antifreeze component, as per InForum. Detectives found a bottle of Windex containing antifreeze in the couple’s garage, matching the poison’s chemical profile, as per Oxygen.

Kenoyer’s claim that Riley drank excessively was contradicted by the autopsy as no alcohol was found in his body, as per the Minot Daily News. Trace amounts of antifreeze were found in a glass of sweet tea Riley drank before collapsing, as per Oxygen.

Kenoyer admitted to investigators that she had spiked Steven Riley Jr.’s sweet tea with antifreeze on September 3, 2023. Her belief that he was set to receive a $30 million inheritance—coupled with the discovery of containers containing suspected antifreeze in their home—led investigators to conclude the act was premeditated.

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5) Kenoyer was convicted and sentenced to 25 years

(Image via Unsplash/@Carles Rabada)

On October 16, 2024, Ina Kenoyer was sentenced to 50 years in prison, with 25 years behind bars and 25 years suspended, with 10 years of supervised probation for the Class AA felony murder she committed, as per InForum. The prosecution highlighted Ina Kenoyer’s greed-driven motive, fueled by a fake $30 million inheritance.

During Ina Kenoyer’s sentencing, members of Steven Riley Jr.’s family—including his son—spoke in court, expressing profound grief and a sense of betrayal over his death. Kenoyer did not apologize or show visible remorse during the hearing and remained silent, as per the Minot Daily News. The conviction brought closure to Riley’s loved ones and $3,455 in restitution, though the community remained stunned by the calculated nature of the crime.

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Stay tuned for more news and updates.

Edited by Bharath S