Stacey Castner placed a call to 911 on August 26, 2005, and the trembling in her voice carried the weight of a panicked wife. She told the dispatcher she had not spoken to her husband, David Castner, since Sunday morning when he locked himself in their bedroom. Officers arrived and forced the door open, finding 48-year-old David dead on the bed. His body was covered in vomit, with a glass of green liquid on the nightstand and an open bottle of antifreeze under the bed.
The scene suggested a straightforward family tragedy, a depressed man taking his own life. The autopsy confirmed antifreeze in David’s system, and the initial conclusion was suicide. As his widow, Stacey stood to inherit everything. David, a successful heating and cooling business owner, had reportedly become depressed after his father’s death and had begun drinking more heavily.
Stacey told police they had argued on the evening of August 19, after which he locked himself in the room. But one investigator, Detective Dominic Spagnoli, was troubled by the details. David worked with antifreeze daily and knew how painful a death by poisoning would be. A firearm was available in the home, making the choice of antifreeze seem unlikely for a man who understood the chemical.
Spagnoli also found it odd that all three fingerprints on the glass containing antifreeze belonged to Stacey, while David’s prints were absent. The investigation soon expanded to include Stacey’s first husband, Michael Wallace. He had died suddenly in January 2000 at age 38, officially from a heart attack. His sister had pushed for an autopsy, but Stacey refused the request, and no autopsy was performed.
Stacey received $55,000 from his life insurance policy and eventually moved on, marrying David Castner in August 2003. When detectives obtained Michael’s medical records, they found he had been in good health, contradicting Stacey’s claims of ongoing health problems. Investigators also discovered that three months before his death, Michael had complained of feeling drunk despite not drinking alcohol, a symptom later identified as a classic sign of antifreeze poisoning. In September 2007, authorities exhumed Michael’s body and found calcium oxalate crystals in his kidneys and liver, definitive evidence of ethylene glycol poisoning.
During a police interview on September 7, 2007, Stacey made what investigators considered a Freudian slip. While looking at a photo of the glasses from David’s bedroom, she said, “Well, I poured the antifreeze,” then quickly corrected herself to say cranberry juice. Later in the interview, she repeatedly mispronounced “antifreeze” as “antiffree,” a pronunciation she would repeat in writing multiple times. As the investigation intensified, Stacey allegedly took a desperate step to deflect suspicion.
In September 2007, she invited her 20-year-old biological daughter, Ashley, to their home for drinks, telling her they had been through a difficult week. Investigators later said Stacey laced Ashley’s drink with ground sleeping pills and alcohol. Over seventeen hours, Stacey allegedly continued forcing her unconscious daughter to consume more medication. A note was found near Ashley’s bed, claiming Ashley had killed both Michael Wallace and David Castner and had attempted suicide.
Ashley survived and told police she had never seen the note and had never attempted suicide. Investigators searched the family computer and found multiple drafts of the note, all created during times Ashley was confirmed to be at school. The draft contained the same misspelling of “antifreeze” as “antiffree” four times, matching the pronunciation error Stacey had made during her interview. Stacey was arrested at the hospital where her daughter was recovering.
In February 2009, a jury found Stacey Castner guilty of second-degree murder in the death of David Castner, second-degree attempted murder for poisoning Ashley, and forgery of David’s will. During the trial, Ashley testified against her mother, telling the court that she did not write the suicide note and had never dealt with antifreeze. The defense argued that Ashley had killed both men, but the prosecution presented computer timestamps linking the note’s creation to times when Ashley was not at home. At sentencing in March 2009, Assistant District Attorney Christine M.
Gervais asked the judge for the maximum consecutive sentences, noting that while Ashley lay dying in her bedroom, Stacey had been celebrating in the backyard with friends. Ashley faced her mother in court and delivered a statement that drew on both love and hatred. She told Stacey that she still loved her even though she hated what her mother had done, and she wished her mother would apologize for the lies. The judge told Stacey Castner that in 34 years in the criminal justice system, he had seen serial killers and contract killers, but she was unique.
He sentenced her to 51 years to life in prison, with no possibility of parole. Stacey showed no visible reaction, simply closing her eyes. After the trial, David Castner’s son filed a civil lawsuit against Stacey and the two friends who signed the forged will. In 2011, a court awarded him over $1.
2 million in damages plus $250,000 in punitive damages, though an appellate court later overturned that ruling. Stacey maintained her innocence throughout her imprisonment and filed multiple appeals, all of which were denied. On June 11, 2016, prison staff found Stacey Castner dead in her cell. She was 48 years old, the same age as David Castner when he died.
An investigation concluded that she had died of a heart attack, with no evidence of suicide or criminal activity. Ashley had said she did not wish to see her mother again before Stacey’s death. The case became a widely studied example of forensic science in American criminology courses. It combined linguistic analysis, computer evidence, and chemistry to prove that the suicide note had been fabricated.
The unique misspelling of “antifreeze” in the note matched Stacey’s verbal mispronunciation, and the timestamps on the computer placed the note’s creation during Ashley’s class hours. The crystals found in Michael Wallace’s body seven years after his death confirmed he had been poisoned with antifreeze rather than dying of a heart attack. David Castner’s family later had his remains exhumed and moved to a different cemetery so he would no longer be buried beside the woman who killed him. Ashley Wallace moved forward with her life, becoming engaged and building a new life away from the media attention.
The case remains a reminder of the dangers of antifreeze poisoning, which can mimic symptoms of intoxication and illness reminiscent of other conditions, and of the importance of requesting autopsies when a healthy young person dies suddenly.