Whitney Houston's autopsy results: What's taking so long?

Singer Whitney Houston performs at last year's pre-Grammy gala & salute to industry icons with Clive Davis honoring David Geffen in Beverly Hills, Calif., Feb. 13, 2011.
AP Photo/Mark J. Terrill
Singer Whitney Houston performs at the pre-Grammy gala & salute to industry icons with Clive Davis honoring David Geffen in Beverly Hills, Calif., Feb. 13, 2011.
AP Photo/Mark J. Terrill

(CBS) What killed Whitney Houston? With unconfirmed reports about the 48-year-old singer's cause of death running rampant, officials have said they will not rule out or confirm a cause of death until they have toxicology results, which can take up to eight weeks to obtain, Reuters reported.

Whitney Houston to be held on Saturday in Newark, N.J.
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That announcement echoes the cases of Michael Jackson and Amy Winehouse: their toxicology screens took up to two months while speculation grew. These high-profile cases have raised the question, why does it take so long to determine cause of death?

"Toxicology labs are often backlogged," Dr. Lawrence Kobilinsky, professor and chair of the department of sciences at John Jay College of Criminal Justice in New York City, told HealthPop. But as far as doing the actual tests and interpreting results, the process ideally should take no more than a week, he said. Kobilinsky said most people aren't aware that these toxicology labs handle lots of other cases, including drug tests for criminal cases or jobs, and they typically don't fast-track cases just because the subject is famous.

"I suspect the popular media has made toxicology tests almost as magical as everything else," Dr. Andrew Baker, president of the National Association of Medical Examiners, told Reuters. "I am sure there are TV shows where they squirt blood into a machine and five seconds later, they get a print out of every drug the person has ever taken. (But) it just doesn't work like that."

How does an autopsy and toxicology test work?

Kobilinsky, who is not involved in Houston's case, says during an autopsy, the coroner looks for obvious signs of death or signs of cardiac problems to determine if death was from natural causes. But some things might not be able to be seen on an autopsy - such as an arrhythmia, for example - which is why coroners spend so much time reviewing all the information and ruling out other causes, with the help of toxicology screens and other tests. The autopsy itself typically only takes about two to three hours, Kobilinsky said.

Kobilisnky said if a lethal amount of drugs or alcohol caused the deaths, the toxicology results would reflect this quickly from tissue sample and blood tests. But sometimes during a toxicology screening, something totally unexpected may come up, pointing to a new cause of death.

"That's what these tests are all about, finding what you may not expect to find," he said. "I think with six to eight weeks they're covering themselves because it's such a high-profile case. They want to dot the i's and cross the t's in case something comes up strange."

Michael Hensen, chief technical operations officer at Pacific Toxicology Laboratories in Chatsworth, said to the Los Angeles Times, "Once the testing is done there's a review process. That could delay the results as well." He said, "There may even be a delay in getting started as they decide what they're going to test for."

Like most Americans, Kobilinsky has seen the media reports change depending on what channel he's flipped on and said if Houston had a lethal amount of alcohol or drugs in her system, then that would be the cause of death. If levels were not lethal but present enough to cause her to fall unconscious in the bathtub where she was reportedly found, then drowning would be the immediate cause of death, secondary to drugs. If Houston had a heart attack, then that would be the cause of death.

The bottom line? The coroner has to decide once all the evidence comes back - so don't believe everything you're reading.

Kobilinsky said the coroners are in the same boat: "Now they just have to sit and wait."