CHICAGO — Can you bear another story about Michael Jackson? What about one with a forensic toxicology angle?

Millions of inquiring minds want to know about the pop star's cause of death. Toxicology experts at the American Association for Clinical Chemistry's (AACC; Washington) annual meeting this week spelled out some of the reasons why it takes so long to determine the cause of death. With rapid point-of-care testing available, many people incorrectly assume that being a superstar is the primary delay in getting to the answer.

"In the hospital setting, a patient can come into the ER and present with specific signs and symptoms. Toxicology testing can be ordered and turned around quickly," said Barbarajean Magnani, MD, chief of clinical pathology and vice chair of pathology and laboratory medicine at Tufts Medical Center (Boston) and chair of the Toxicology Resource Committee at the College of American Pathologists (Northfield, Illinois).

"Point-of-care systems are usually screening tests that support the clinician's diagnosis," she said. "The type of testing in this case is forensic and is more involved."

Forensic toxicology is the post-mortem testing for lethal and/or foreign substances in body fluids and tissues, and it can be a very time-consuming process. Reasons for that slow process – which can take weeks – range from the extensive record keeping that is needed for forensic defensibility of the toxicology studies underlying a final report to the simple fact that some tests may be beyond the scope of expertise in the initial lab that received the specimens and those specimens then have to be referred to more specialized reference labs.

"Typically we screen the urine and heart blood for drugs," said Fred Apple, PhD, director and professor of lab medicine and pathology at the Hennepin County Medical Center (Minneapolis) as well as clinical toxicology consultant at the Hennepin Medical Examiner's Office. "We do 4,000 cases a year and 25% are toxicology related. We screen within a week or two and then talk about what was identified. Then the medical examiner meets with a toxicologist to decide what needs to be quantitated. We bring the specimens back to the lab. Usually we have a three-week turnaround. But we're a small operation. Eighty percent of the time we can use our technology in house – mass spectrometry, gas chromatography – to quantitate a drug and that may take three weeks."

Apple and Magnani led a presentation at the AACC designed to sneak a peak behind the curtains as medical examiners in California try to determine Jackson's death via toxicology studies.

Both pointed out that forensic testing demands a chain of custody so that for each step, from collection of the specimen to the final report, there is documentation of where the specimen has been and who handled it.

The precise process starts when toxicology reports are issued after a death investigation. But in certain circumstances, new information may become available and the toxicologist may have to test for additional drugs, or test other samples before the report is finalized.

"If it's a medical legal case that might go to court, they want the numbers," Magnani said. "Each individual drug may not have a high enough concentration, but many drugs are additive. Opioids, when mixed, can cause a higher concentration."

Apple said that if someone is found dead after filling four to five prescriptions – known therapeutic drugs that typically wouldn't have an adverse effect – sometimes they mix drugs that might build up toxic levels. Or a person can take a therapeutic dosage but with another drug added in, it changes the effect and becomes toxic.

"We see a lot of polypharmacy in celebrities," Magnani said.

But why does the toxicology testing take so long? It's the details, quality control and reporting requirements. And that's assuming nothing runs afoul during testing in which case you have to start all over.

"The analytical part of the lab is not CSI [the TV drama]," she said. "Most of these labs are certified and you have run controls, it's not just about getting the numbers out. If one quality control is out on a run, you have to go back and start from ground zero."

Apple said the most progressive technologies currently in use by toxicologists are mass spectrometry and gas chromatography. And while these aren't new technologies, they have been refined and significantly reduced in size in the last several decades.

"We use bench-top instruments now," Apple said. "When I started off in 1980, our mass spectrometry machine was the size of room."

So given the current state of forensic toxicology testing, the fact that a final report has yet to be produced on Jackson's death is not surprising to these two toxicology experts.

"I suspect they've done their screening and they know what drugs are on board," Apple said. "They're probably sending it out to reference labs and making sure or maybe they got some report findings that were unexpected. Either way, they're being extra cautious because it's a high-profile case."