Diane Staudte resided in Springfield, Missouri with her spouse Mark and their four offspring.
A trained nurse, Diane worked closely with the church and was the main provider for the family, while Mark, a musician, took care of their children.
Everything changed on Easter 2012, when Mark passed away suddenly from what doctors believed to be natural causes.
There was a circle of blood around his mouth, but his death was not looked into, and his body was cremated.
Per ABC News, Diane Staudte obtained $20k from Mark’s life insurance and relocated the family to a better house in a different neighborhood. Tragedy struck again only five months later.
Her 26-year-old son Shawn died without warning.
Her pastor later told investigators that he found it unusual that Diane appeared to be hosting a celebration at her husband’s funeral and didn’t arrange a funeral for her son at all.
However, when Diane’s daughter became ill in June 2013 and was admitted to the hospital, the pastor made an anonymous call to the police.
Springfield police detective Neal McAmis informed People in 2016, “He (the pastor) discussed Diane’s lack of emotion when Mark passed away. He found Diane’s reaction after Mark’s death to be strange.”
McAmis mentioned the pastor telling him about his relatively close relationship with Mark and him being unaware of any reason for Mark’s passing.
But, after Shawn, a healthy young man, passed away, that’s when he witnessed a complete lack of emotion and started to become suspicious,” McAmis stated.
The pastor, Jeff Sippy, revealed himself for the first time years later and in a sitdown interview for 20/20 to be aired on February 25, 2022, he talked further about his suspicions.
“There was nothing in me that believed that it was of a natural cause,” Sippy stated in his first-time speaking publicly about the Staudte case. “I didn’t believe that he died of a stroke. A heart attack. Or in his sleep. I just didn’t.”
“There’s nothing scientific. There’s nothing professional about my observation. But my first words were ‘no way.’ He did not just die.“
Diane Staudte, The Murderess of Her Spouse And Son
Police conversed with an unnamed informant, later identified as Pastor Jeff Sippy, who indicated that he suspected Diane Staudte murdered her son and her husband and was attempting the same with her 24-year-old daughter Sarah.
He mentioned believing that Sarah’s demise was imminent, and police hurried to the hospital to converse with the doctors and staff.
They were informed that Sarah had complained of flu-like symptoms, but she also suffered from liver and kidney failure, consistent with poisoning.
“I ended up speaking with a doctor that was taking care of Sarah as well. He had told me that they performed several tests,” McAmis stated during an interview on the upcoming 20/20 segment.
“They couldn’t figure out what was going on. And he said that he was suspicious that it was a possible poisoning case.”
Investigators probed into Mark and Shawn Staudte’s deaths and found they both had the same telltale sign of a ring of blood around their mouth at their time of death.
The Springfield Police Department brought in Diane Staudte and her daughter Rachel Staudte for questioning.
Interrogation tapes were obtained by ABC News and demonstrated Diane Staudte initially repudiating any misconduct.
“‘I didn’t hurt my kids and that’s what I feel like you’re insinuating I did. I may not be the best mother in the world, but I didn’t hurt my kids,” Diane told McAmis. “When Mark died, it was actually a relief. I just don’t tell people that. I don’t know what else to say.”
However, after she was read her Miranda rights, she confessed to putting antifreeze in her husband’s drinks and doing the same to her son.
She expressed being weary of her husband and desiring him out of the picture. When McAmis inquired why, she said, “By then, I hated his guts. He would throw things at me. He would throw things at the kids. I guess I’d just had enough.”
Her son, Shawn, grappled with a history of seizures and autism, and Diane Staudte described him as a “significant burden” to her.
“Shaun would be interfering with whatever I would do,” Diane told McAmis. “He was more than a bother … more than a pest.”
She had started poisoning her daughter with antifreeze because she had considerable college debt she didn’t want to pay.
When police questioned Diane’s daughter Rachel, she denied any wrongdoing, but after she was read her Miranda rights and a page from her personal diary, her account changed.
The diary entry was dated June 13, 2011, almost a year before Mark Staudte died. “It’s sad when I realized how my father will pass on in the next two months,” her diary entry stated.
“Shaun, my brother will move on shortly after. It will be tough getting used to the changes, but everything will work out.”
McAmis mentioned in the 20/20 interview, “Rachel said that her mother was the only one that understood her. They could relate to each other … Rachel was the golden child, and it was just going to be those two.”
Where Is Diane Staudte Now?
Diane Staudte and her daughter Rachel were found guilty in 2015 for the murders of Mark and Shawn Staudte and the attempted murder of Sarah Staudte.
Rachel Staudte accepted a plea deal of life in prison with the possibility of parole if she testified against her mother.
She accepted the deal and was sentenced in 2015 for the second-degree murder of Mark and Shawn Staudte.
Diane Staudte pleaded guilty to the first-degree murders of her husband and son and was subsequently sentenced in 2018 to life in prison without the possibility of parole.
