But the anticipating public shouldn't hold its breath. As with the long line of celebrity overdoses that came before, like Michael Jackson, Heath Ledger and Anna Nicole Smith -- toxicology reports pronouncing the cause of death for these two young celebrities will not be released for weeks, possibly months.
But experts say the delays are often caused by a combination of overwhelmed toxicology labs, and cautious prosecutors, not by the length of the testing procedures.
Does it really take that long to run most of these drug tests? According to forensic pathologist to the stars, Dr. Cyril Wecht, "Certainly not."
"It does not take several weeks," says Wecht. "That's sheer nonsense. Most of the time they tell the media that to get them off their backs.
"If the autopsy is done in the morning, the specimen is at the lab by lunchtime, and in my opinion, within 48 hours -- once the test are started -- they have a pretty good idea of what drug and how much," Wecht says concerning cases involving prescription drug overdoses.
"We're not dealing with rare cobra venom or the saliva from a South American frog," he adds. "We're dealing with Demerol or Oxycodone -- these are drugs people take all the time."
In an emergency room, he points out, "they will draw blood and submit to their lab and they'll have responses back in a few hours, because it's a matter of life or death [they need to know] how to treat the patient."
While he admits that a long line of backlogged cases can contribute to the delays often experienced at toxicology labs, in the case of basic drug tests for high profile deaths, "I guarantee you, within one to two days, they've got the results back on their desks."
But often autopsy toxicology tests -- even for overdoses of common drugs -- can be more complicated than expected, toxicologists say.
According to Ruth Winecker, chief toxicologist for the state of North Carolina's Office of the Chief Medical Examiner, the scope of laboratory testing for a forensic screening is much wider than for hospitals.
"Hospital clinical labs generally are screening for five to 10 drugs but...a forensic lab is screening for several hundred drugs and toxic substances."
Additionally, toxins or drugs for an autopsy report have to essentially be tested twice, once in the initial screening and once in a confirmation assay, which will "unequivocally identify the drug or toxin and quantify the amount present," Winecker says.
Unlike medical cases in emergency rooms, toxicologists have to produce results that are "valid, reliable, and defensible in a court of law," says Dr. Bruce Goldberger, director and professor of toxicology at the University of Florida. To get the kind of conclusive results necessary, "many of the procedures utilized take days to perform," he says.
Add on top of this, experts says, that forensic toxicology laboratories are under-resourced and understaffed, and the build-up of cases can be overwhelming.
"There is usually a backlog...that will delay the start of testing on new cases," says Winecker, and most laboratories have a backlog reaching back weeks or even months, Goldberger adds.