North Dakota woman pleads guilty to poisoning longtime boyfriend over $30 million inheritance

A North Dakota woman pleaded guilty Wednesday to killing her boyfriend of a decade by poisoning him because she believed he was going to leave her after inheriting $30 million, according to court documents and officials.

Ina Thea Kenoyer, 48, was arrested Oct. 30, and charged with killing Steven Edward Riley Jr., 51, the previous month, according to the Minot Police Department. Police believed Kenoyer “had financial motives to murder Riley.”

On Sept. 3, Riley went to the airport with friends to meet a lawyer because he believed he was going to receive a large inheritance, according to an arrest warrant affidavit filed in North Dakota’s north central judicial district. His friends told investigators he planned to leave Kenoyer, who he had been dating for around 10 years, after receiving his inheritance.

Another friend told investigators that Kenoyer was throwing his belongings out of the home they shared that afternoon because she was upset that Riley was going to break up with her after receiving what she believed was an inheritance of over $30 million dollars, according the affidavit. It’s not clear if Riley had actually inherited a large sum of money.

At the airport, Riley told his friends he felt drunk despite not having any alcohol, complained about stomach pain and was nearly falling over while trying to walk. They wanted to take him for medical treatment but Kenoyer, who claimed to have medical training, said Riley “was suffering from heat stroke and just needed to go home and rest after the airport,” the affidavit states.

The next day, an ambulance was called to a Minot, North Dakota, home, where Riley was found unconscious. He never regained consciousness and died Sept. 5, according to the affidavit.

An autopsy determined his cause of death was poisoning, police said.

An attorney for Kenoyer did not immediately respond to a request for comment.

Riley’s family and friends told police that they were concerned Kenoyer had poisoned him with antifreeze because she had made comments about in the past, as well as comments following his death that he was poisoned, despite not receiving any information about his condition from medical professionals, according to the affidavit.

Following Riley’s death, Kenoyer told detectives she considered herself his common law wife and planned on splitting his inheritance with his son. When she was told that North Dakota doesn’t recognize common law marriage and that she wasn’t entitled to Riley’s inheritance, Kenoyer became enraged, the affidavit stated.

Kenoyer also told detectives she had made Riley sweet tea on the day he fell ill, which easily disguises the ethylene glycol in antifreeze, according to the affidavit.

Kenoyer was taken to Ward County Jail following her arrest and charged with felony murder. She pleaded guilty to intentional murder with extreme indifference. She is scheduled to be sentenced on Aug. 13, court documents state.

An attorney for Kenoyer did not immediately respond to a request for comment.