A method of murder or suicide which might be undetectable to medical examiners? A substance possibly known to AC and which was easy to obtain? Here's my latest theory (warning: JMO, speculation, and long):
Prior to the release of AC's autopsy results there seemed to be two main camps within the WS community re: AC's death: murder or suicide. Althouugh there was no evidence at the scene indicating foul play, I think many sleuthers remained unconvinced.
In several posts before the autopsy results were released, I speculated that AC's death had been a suicide. My reasoning was that 1.) AC seemed too young to have suffered either a heart attack or stroke, 2.) AC was likely burdened by tremendous guilt and shame, and was under enormous stress, 3.) LV and CD were out of the country at the time of AC's death, 4.) AC might've felt he could protect his sister and CD and earn the admiration of the 144k by taking his secrets with him to the grave, 5.) AC might've owned a life insurance policy and wished to have some specific individual receive the payout (policy payouts appeared to be at least one of the motives in earlier incidents involving CV, BB, and TD).
If AC did kill himself, I think there is good reason to think he may have wanted to conceal the real cause of death. A finding of suicide might make any life insurance benefit payout null and void. A finding of suicide might harm AC's reputation among relatives, friends and the group. And a finding of suicide might later be interpreted by both the public and LE as an admission of guilt.
On the other hand, a finding of death by natural causes would likely confuse and hinder any/all LE investigations into AC or the group. AC could have feigned his symptoms of chest/lung illness in the week leading up to his death as part of a plan to conceal the manner of death (even in his discussions with MG on the phone).
When AC's autopsy results were finally released, I think many sleuthers were in shock. How could the medical examiner have missed finding something (anything!) in the course of the investigation - when it was known in advance that certain dynamics were in play in which foul play or suicide might very well have played a part in AC's death, and that if foul play was involved, certain imfividusls might then have attempted to conceal the true manner of his death?
Afterwards though, I stuck to my guns and suggested that AC had perhaps killed himself by injecting air (aka an air embolism), resulting in a PE. I theorized that injecting air had been used may times in past murders and suicides, and that the technique might leave little evidence behind for an autopsy to find. The problem was, while an air embolism might've fit in AC's death, it really didn't fit in TD's - and while we still didn't (and don't) have TD's autopsy report back yet, I'd always felt that she and AC were perhaps killed in the same manner (again, assuming both deaths were not simply due to natural causes).
Today while online I came across a method and a substance which I think might fit the circumstances of both both TD's and AC'S's deaths (coughing, vomiting, shortness of breath, chest pain, pink film). The substance is called HCF-134a (otherwise known as Trifluoroethane). HCF-134a is a common refrigerant, and is the main ingredient in "compressed air dusters" (aerosol cans of compressed gas used to dust off computer keyboards and interiors, electronics, lenses, machinery, etc). For those purposes, "compressed air dusters" can be purchased at any office supply store or big retailer. HCF-134a is also used as a propellant in air soft and paintball guns.
Intentionally inhaling compressed "air" (known as "huffing" or "dusting") from a compressed "air" duster can be fatal. Again, this is because "compressed air dusters" don't actually contain compressed air, but rather a high density refrigerant gas called HFC-134a. Think freon. In fact, HFC-134a has been used as a replacement/substitute for freon since the late 90's when concerns arose sbout damaging the ozone.
Tragically, some young people have died while trying to get high via "huffing" or "dusting". The high is actually hypoxia, which I read is caused by a kind of shuffling
of O2 and CO2 in the bloodstream. This condition occurs when air in the lungs is suddenly displaced by the denser HFC-134a gas as it rapidly sinks to the bottom of the lungs. Asphyxia follows, often occurring in minutes. I don't know whether HFC-134a (also known as Freon 134a) would be detectable during an autopsy or in blood panels.
I also don't know whether AC was an air soft / paintball enthusiast when he was living down in AZ. A quick search online though and you'll get the impression that Phoenix just might be the air soft /paintball capitol of the world. And then of course there's the suspicion that maybe AC was "paintball dude", standing and firing blanks (or missing altogether) at TD as she unloaded frozen dinners from the back of her SUV one night about 2 weeks before her sad death.
There are other compressed gasses (CO2) which are used as propellants in air soft and paintball guns, so maybe it's a long shot theory. But if AC was an air soft /paintball enthusiast, I think it's just possible thst he might have known about HFC-134a: an odorless, colorless gas - that kills quick.
Eta: A method that might've first been tried (with apparent success, if it was) on JR..
But I promise to be good!
