A North Dakota woman was charged with murder on Monday over allegations that she fatally poisoned her boyfriend with antifreeze in an effort to claim part of his $30 million inheritance.
Ina Thea Kenoyer, 47, is accused of orchestrating the Sept. 5 death of her boyfriend of 10 years, Steven Edward Riley Jr., 51. A police affidavit alleges that Kenoyer told authorities that Riley had suffered from heat stroke when he became ill, but an autopsy later found that his death was caused by poisoning from ethylene glycol, the main chemical used to make antifreeze.
Authorities were called on Sept. 4 to the couple’s home in Minot, where Riley was found unresponsive, according to the affidavit reported by The New York Times. He was taken to a hospital in Bismarck, where he died the following day.
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Riley’s friends and family told authorities that they believed Kenoyer had killed Riley with antifreeze and that she’d even made comments before and after his death about using the toxic substance to poison him. Investigators also reportedly found that Riley was planning to leave Kenoyer once he’d received his multimillion-dollar inheritance.
One of Kenoyer’s friends reported seeing her dumping Riley’s possessions outside their house on the day he became ill, adding that Kenoyer was upset that Riley was planning to take the money and leave her.
After his death, Kenoyer also allegedly told authorities that she was entitled to some of the inheritance on the grounds that she was Riley’s “common law” wife. Although some states do recognize “common law” marriages, in which a couple who have been together for a long time can be considered married without ever having an official marriage, North Dakota isn’t among them. Kenoyer became “incensed” when investigators explained that to her, according to the affidavit.
Riley had gone to an airport on the evening of Sept. 3, the day before he was rushed to the hospital, to meet with a lawyer and finalize his receipt of the inheritance.
Kenoyer and some of Riley’s friends were also at the airport with him when he suddenly became ill, saying that he felt drunk without having had any alcoholic drinks. The affidavit says Riley complained of stomach pain and almost collapsed, and that witnesses wanted him to receive medical attention.
Instead, the document says, Kenoyer was adamant that Riley was “suffering from heat stroke and just needed to go home and rest.” The following morning, a friend went to the couple’s house to see how Riley was doing. Kenoyer allegedly told him that Riley was at a walk-in clinic—but after the friend went to every walk-in clinic in Minot as well as the ER, he was unable to find him.
Kenoyer told authorities that Kenoyer had been drinking throughout the day on Sept. 3 and had suffered heat stroke on Sept. 2, but a friend who had been with him on Sept. 2 said he hadn’t had heat stroke. Toxicology tests also found no alcohol in Riley’s system at the time of his death.
Searching the home, investigators found a bottle of Windex containing a green liquid believed to be antifreeze along with a beer bottle and a plastic mug that were also suspected to have contained the substance. Detectives also said Kenoyer acknowledged serving Riley sweet tea on Sept. 3, with authorities noting that antifreeze can be difficult to detect in sweet drinks.
For her own part, Kenoyer floated several ways in which Riley may have ended up accidentally consuming antifreeze, including smoking a cigarette that “may have fallen into antifreeze in the garage.” She also allegedly claimed that heat-stroke symptoms “mimic poisoning.”
