The Missouri podiatrist who died suddenly in January – just over three years after her fiancé's former lover was also found dead in mysterious circumstances – succumbed to a fatal drug overdose.
Sarah Sweeney, 39, who was found dead in a home in the Westwood neighborhood of St. Louis on the morning of Jan. 13, died of oxycodone, gabapentin and diphenhydramine poisoning, said the Frontenac police department.
Oxycodone is a narcotic pain reliever, while diphenhydramine – often sold over the counter under the brand name Benadryl – is for allergy symptoms and gabapentin is an anticonvulsant.
It is not immediately clear whether Sweeney took these medications regularly, although her mother, Teresa Sweeney Light, previously told Fox News Digital that she had health problems resulting from mast cell activation syndrome.
There were no obvious signs of trauma to her body and evidence indicates she was home alone in the hours before her death, the statement added.
The circumstances of Sweeney's death, however, remain undetermined.
“Investigators continue to gather information; therefore, this matter remains an active investigation,” the update concludes.
Sweeney was found dead in the home where she lived with her fiancé, local fire Capt. Robert Daus, according to public records.
Nearly four years earlier, in July 2020, Daus called first responders to his previous address in Creve Coeur to report that his then-fiancée, Grace Holland, had allegedly shot herself in the head in front of him.
Holland – who had four children – was later determined to have committed suicide.
His family disputed that finding and sued Daus for wrongful death – citing evidence that he controlled Holland's finances and threatened to end their relationship.
When Sweeney moved in with Daus, she expressed some concerns about his troubling past.
“I had to move in with my boyfriend the 'murderer' (sic), which was scary at times,” she wrote to a former colleague and friend, Danielle Mankunas, in March 2022.
At the time, Sweeney was considering suing his former employer and was trying to persuade Mankunas to support the suit despite the financial and professional risks.
This case was still pending at the time of Sweeney's death.
Sweeney's relationship with Daus also caused her to become estranged from her mother and stepfather, Sweeney Light told Fox in January.
Those close to her had forwarded articles about Daus' ties to Holland, but she eventually stopped responding, the grieving mother said.
“She was an adult, a doctor and a woman. We didn’t know what to do,” she said at the time.
When reached by the Post Wednesday morning, Sweeney Light said the family has “complete confidence in the thorough investigation conducted by the St. Louis County Medical Examiner's Office and the Frontenac Police Department.” .
“Our hope is to close this chapter in our lives so that we can grieve, move forward and continue to honor the memory of our Sarah,” she added.
Robert Daus did not immediately respond to The Post's request for comment.