Home » North Dakota Woman Accused of Fatally Poisoning Boyfriend for His Inheritance

North Dakota Woman Accused of Fatally Poisoning Boyfriend for His Inheritance

A North Dakota woman is accused of fatally poisoning her boyfriend with antifreeze to claim a hefty sum he was set to inherit. 

Ina Thea Kenoyer, 47, was arrested Monday in connection with the man’s death in September, Minot police said in a statement Tuesday.

She has been charged with murder and is being held at the Ward County Jail, police said. 

Kenoyer’s boyfriend, Steven Edward Riley Jr., 51, also from Minot, died Sept. 5 at a Bismarck hospital. He was initially taken to Trinity Hospital but was transferred to the Bismarck hospital — because his condition was “so severe,” according to the case affidavit — where he later died, police said. 

“Ina Thea Kenoyer did not obtain any medical treatment for [Riley] until the next afternoon even though she had over 12 hours alone with [Riley] and watched his health decline to where he was unresponsive and died less than 24 hours later,” the affidavit says. 

Police said an autopsy determined Riley’s cause of death was poisoning. When the coroner was made aware of a possible antifreeze poisoning, officials tested for ethylene glycol — an ingredient in antifreeze — and found “toxic levels” in his system, according to the affidavit. 

Investigators found a Windex bottle without a top that contained a bright green liquid in the living room of the couple’s home, as well as a glass beer bottle and a plastic mug in the garage that contained the same liquid, suspected to be antifreeze, according to court documents. 

Kenoyer later told investigators there were a number of ways Riley could have died from antifreeze poisoning, including “smoking a cigarette that may have fallen into antifreeze in the garage,” according to the affidavit. 

Kenoyer said she served Riley sweet tea “throughout the day” on Sept. 3, officials said. According to the affidavit, ethylene glycol makes antifreeze sweet and “is easily disguised in sweet drinks.”

After his death, Riley’s family reported concerns about Kenoyer to the police. They thought she had poisoned him with antifreeze, according to the affidavit, because Kenoyer had made comments about it over the course of the couple’s 10-year relationship. The court documents say his relatives reported that Kenoyer made comments about Riley’s being poisoned even before tests had been run or medical professionals had updated her about his health.

According to the affidavit, Riley’s friends reported that he planned to meet with a lawyer at an airport on Sept. 3 about completing the transaction to receive an inheritance. The friends thought Kenoyer was aware of the inheritance and believed it was worth more than $30 million, the court documents say.

She told investigators she planned to split the money with Riley’s son, according to the affidavit, adding that she believed she was entitled to some of the money because she considered herself Riley’s wife.

His friends indicated to police investigators that Riley was planning to break up with Kenoyer after he received the inheritance, the affidavit says. A friend of the couple’s reported seeing Kenoyer throw Riley’s property outside on Sept. 3 because she was mad the man was going to get his money and then leave her, the document states.

His friends told police that later that night, Riley declined rapidly, he complained that he felt drunk despite being sober, he had stomach pain, and he was falling over when he tried to walk. When the friends tried to get him medical attention, Kenoyer would not let them, insisting her boyfriend was suffering from heatstroke and needed rest, the affidavit said. 

An hour later, Riley was vomiting, he could not walk on his own, and he was going in and out of consciousness, friends told investigators, according to the affidavit. 

Kenoyer told investigators that she wanted to get him medical attention but that one of Riley’s friends told her not to. 

Kenoyer had reported that Riley was drinking alcohol “all day” Sept. 3, but no alcohol was found in his system, court records say. His friends reported that he did not show any signs of heatstroke, as Kenoyer had claimed. She also claimed she Googled the symptoms of heatstroke and noted to investigators that they can “mimic poisoning,” the affidavit said; investigators also Googled the symptoms of heatstroke “and found absolutely no reference to ‘mimicking poison.'” 

It was not immediately clear whether Kenoyer had an attorney who could comment on her behalf. Her first court appearance and arraignment are set for Dec. 7.