Newly released court documents reveal the alleged plan devised by Jonathan Hearn and Sabrina Limon to poison Sabrina's husband Robert.
The poisoning attempt took place a few months before police say Robert was shot and killed by Hearn at a Tehachapi rail yard in August 2014.
The documents detail Hearn's account of the events, beginning with Hearn telling investigators that Sabrina "always" said divorce was not an option and that Robert would rather die than be divorced.
Hearn told investigators that Sabrina was worried about the stigma that being divorced would have on her image and believed many friends that her and Robert shared would side with Robert.
The documents say talk of killing Robert started as a joke before Hearn says Sabrina's discussion of the topic became "dark and eroded".
Hearn told investigators the two decided on poisoning Robert after discussing a car accident and fire as other ways to kill him.
Hearn added that Sabrina told him that Robert had a rare medical issue that caused stomach issues and vomiting. They believed the poison could go undetected because of the medical issue and the symptoms.
Hearn told investigators he began to research arsenic and how much dosage would be needed to kill a man. Hearn said he used a fake name and prepaid card to purchase the arsenic from a company that did not require a background check.
The documents show that Hearn tested the poison on a neighborhood dog who he believed was noisy. Hearn said he stopped hearing the dog days after he administered the poison, and believed the dosage had worked.
Hearn told investigators that during this testing stage, Sabrina began to pressure Hearn so that they could go through with their plan.
The documents say that Sabrina made banana pudding, which was Robert's favorite dessert, with the intent to put the arsenic in it so that he could eat it at work.
Hearn added that Sabrina wanted to poison Robert away from their home so that she would be less likely to be investigated. Hearn told investigators that Sabrina told him the Tehachapi hospital is a "little disorganized" and she did not believe they would find arsenic in his blood.
After placing arsenic in the pudding, Hearn told investigators that he and Sabrina began to worry that detectives could trace their calls and determine that they worked together to poison Robert.
The document says Hearn later asked Sabrina what had happened with the pudding. He told investigators that Sabrina said she had told Robert to throw the pudding away because it did not taste good and she had made an error when she was making it.