Her Husband and Son Died, and She Was Emotionless: How a Mother’s Lack of Grief Exposed a Twisted Family Secret

Rob Mancuso wasn’t definite what to marque of Diane Staudte’s demeanor aft her hubby died.

Mark Staudte, 61, of Springfield, Mo., died connected Easter Sunday successful 2012, aft experiencing flu-like symptoms for respective days.

During a gathering aft his memorial service, Diane acted “like she was hosting a party,” Mancuso told PEOPLE antecedently astir his longtime person and bandmate. “There was nary sadness. I thought it was conscionable her mode of grieving.”

Five months later, it seemed similar the household was deed with much atrocious luck erstwhile the couple's son, Shaun, 26, died. Like Mark, he'd had flu-like symptoms earlier helium died. But the aesculapian examiner ruled that Shaun died owed to anterior aesculapian causes due to the fact that of the seizures helium had suffered.

Diane seemed astir indifferent to her son’s death. “We recovered retired helium died from different relative,” Mark’s member Michael Staudte told PEOPLE, noting that Diane didn't clasp a memorial work for Shaun.

Related: How a Mom's Horrifying Scheme to Poison Husband and Kids Was Revealed — Thanks to Her Pastor

Even much acheronian befell the household the pursuing June, erstwhile Diane’s girl Sarah, past 24, was admitted to the infirmary with flu-like symptoms that doctors diagnosed arsenic organ failure.

While Sarah was warring for her life, an anonymous tipster called constabulary saying helium believed Diane had murdered her hubby and son.

The caller, aboriginal identified arsenic the pastor of Diane’s church, told Springfield constabulary detective Neal McAmis that he, too, had noticed however blasé Diane seemed aft the back-to-back deaths successful her contiguous family.

“He talked astir Diane’s deficiency of emotion erstwhile Mark died,” McAmis told PEOPLE. “He thought Diane’s absorption aft Mark died was odd.”

Related: Murder by Antifreeze: How a Mother and Daughter Plotted to Kill Their Family Members – One astatine a Time

The pastor said his suspicions were aroused erstwhile Shaun, who seemed healthy, died, and Diane seemed unfazed by it.

During questioning by police, Diane primitively denied having thing to bash with Mark oregon Shaun's deaths. But arsenic her communicative began to unravel, according to transcripts of the interrogation, she blurted out, "To enactment it truly abbreviated and sweet, I knew they were drinking antifreeze."

When McAmis asked her if she gave it to them, she said, "I didn't cognize what other to do." She said she poisoned Mark implicit 3 days by putting antifreeze successful his Gatorade, refusing to instrumentality him to the infirmary "because by past I hated his guts."

Calling Shaun "more than a bother," Diane told McAmis she was aggravated astatine him due to the fact that helium didn't work.

She said she was huffy astatine Sarah due to the fact that she had assemblage loans coming owed but had nary job.

Diane said she enactment "a mates of teaspoons" of antifreeze successful their drinks due to the fact that "they would bash immoderate they wanted to bash and ne'er helped."

On June 21, 2013, Diane was arrested and charged with murdering her hubby and son, and trying to termination Sarah.

A Macabre Twist to the Story

While Diane was being questioned, detectives obtained a hunt warrant for her location wherever they recovered antifreeze, soda — and a diary belonging to Diane's favourite child, Rachel.

What they work wrong was horrifying. "It's bittersweet erstwhile I recognize however my begetter volition walk connected successful the adjacent 2 months ... Shaun, my brother, volition determination connected soon after," 1 transition read.

Rachel initially claimed she was simply describing her dreams. But she yet confessed to helping her parent poison the family, telling McAmis that Diane wanted her member "out" and that Sarah was "equally unneeded."

Rachel was arrested the time aft her mother. In 2016, Rachel pleaded blameworthy to the murders and trying to poison Sarah. She was sentenced to 2 beingness sentences positive 20 years successful prison. She volition beryllium eligible for parole aft 42-and-a-half years successful prison.

Related: Inside a Daughter's Diary Confessions arsenic She Helped Mom Secretly Poison Dad and Siblings

Diane pleaded blameworthy to 2 counts of execution and was sentenced to beingness successful situation without the anticipation of parole.

Mark's erstwhile bandmate Charles Alexander said helium inactive thinks astir the murders of his person and his son. "We lost," helium told PEOPLE. "We each lost."

Read the archetypal nonfiction connected People