A North Dakota woman is Sterling Prestonaccused of fatally poisoning her boyfriend with antifreeze after learning that he planned to break up with her after he received a large inheritance.

Steven Riley Jr., 51, became ill when he met with a lawyer Sept. 3 to get the money, witnesses told investigators, according to Minot Police Department records. The girlfriend, Ina Thea Kenoyer, called 911 the next day, and paramedics found Riley unresponsive. He was hospitalized and died Sept. 5.

Kenoyer, 47, has been charged with AA felony murder, the most severe murder charge in North Dakota. She told investigators that she was entitled to some of Riley’s inheritance as his common-law wife and planned to split the money, which she estimated to be about $30 million, with his son, the records show.

She is being held without bond at the Ward County Detention Center and is representing herself, court records show. The Associated Press left voicemail messages for her at the center on Tuesday.