Honest question: Did no one else suspect that "another person" might have been involved in some way?
Yes, of course. There was an extensive police investigation. The first person they always investigate is the husband. They also investigated Mary's son, who had mental health problems.
No one ever suspected the clinic assistant, this very nice young woman who'd had a 'toxic relationship' with Mary's son.
However, what police really investigated was to find concrete evidence about who could have acquired and given Mary such a large dose of the unusual prescription-only drug that killed her. It was not a drug you could just buy at a store or off the street.
They traced the purchase of this drug to Mary's own clinic, and followed a convoluted trail of how it was purchased, and what happened to it.
They believe the accused made extensive efforts to conceal her own involvement and pin it on Mary's son, her former boyfriend. However, she didn't know he was out of town when Mary consumed the poisonous dose.
So, the case against her is based on the theory that she was very conniving, was really trying to punish Mary's son for breaking up with her, and didn't mind killing Mary, even though she was kind to her.
This case, if true, reminds me of the Australian deathcap mushroom poisoner, who didn't mind killing perfectly nice, kind people, and came across as such a 'nice' woman that no one could ever suspect her.
I wish I could cite a MSM source, but they seem to be just milking the melodrama to the max, rather than actually referring to the evidence.
BTW, the primary reason she won her appeal is "ineffective counsel" ie her claim that her defense attorney was incompetent. IMO, in awarding the appeal, the judge is not confirming that the defense lawyer was actually incompetent, but just allowing for that possibility, and therefore challenging the prosecutors to retry her again...
JMO