Contra The Writer and Rider Nicole: this is to let my readers know that I will not be commenting on the death of Anna Nicole Smith. Except to say that sudden unexpected deaths are surprisingly common in my experience.
Of course, the forensic nature of my practice for some years now has probably skewed my statistics. There are a surprising number of people who die suddenly and unexpectedly, probably from some unexplained cardiac mechanism, even under the age of 40. If the truth can be told, not always a prudent thing to do these days, a lot of older folks also die suddenly and not quite so unexpectedly from the same causes. They often have accompanying coronary artery disease which, because it is visible, makes it easy to assign it as a causative mechanism.
In the younger age group, whether suicide seems unlikely or not, there are a fair number of deaths associated with drug use. The mechanism isn’t always clear as a simple overdose is often not the answer. I suspect that a lot of drug users become habituated to large doses, then for various reasons, cut the dose, or stop taking the drug for awhile, long enough for their tolerance to drop, or maybe they just have some interfering illness. When they resume their usual drug habits at a relatively high level their tolerance does not have a chance to build up slowly: perhaps they develop a sudden cardiac arrhythmia from which they do not recover and the coroner gets called because they “woke up dead.”
The long time interval for the toxicology studies to be done is probably due to the lab’s deliberate policy to encourage their political masters to give them more money. The website below leads one to standard forensic pathology texts.
though I would not advise going there unless you have a morbid curiousity.