So how does a newspaper write an obituary for a promising physician whose death has been attributed to a mysterious - and so far unresolved - cyanide poisoning?

Here's the way the Pittsburgh Post-Gazette handled it last week:

Autumn Marie Klein, a physician in the forefront of treating pregnant women with neurological diseases, collapsed at home in Oakland and died Saturday at UPMC Presbyterian. She was 41. Results of an autopsy are pending.

It's actually a rather lovely piece, full of grief and generous tribute, as a good obit should be. The unlovely information, by contrast, appears in the paper's news section, starting with this storywhich reveals that tests at UPMC (University of Pittsburgh Medical Center) had turned up a "toxic level" of cyanide in the dead doctor's blood.

(If you follow that link, you'll I provide some general background on cyanide poisons in the story. I've spent a surprising amount of time on that subject, in part due to another mysterious cyanide death in Chicago, the still unsolved murder of a very unlucky lottery winner.) But there's more detailed and specific analysis in later stories, discussion of a widening police investigation in this one, suspicions of suicide inthis one.

As that last story points out, cyanide is not that accessible a poison in this country; it's a controlled substance due to its well known dangers. The term cyanide actually refers to a tidy carbon-nitrogen (CN) bundle. That compound bonds with other chemicals, forming some of our most famous poisons, most notably hydrogen cyanide (HCN), the lethal gas that the Nazis employed in World War II concentration camps. In other words, HCN made cyanide notorious. According to the Organization for the Prevention of Chemical Weapons, it was also usedby Iraq against rebels and enemies. And, as I wrote in a recent piece for Medium, it was employed by the USSR during the Cold War to eliminate dissidents.

We encounter hydrogen cyanide in cigarette smoke and in house fires, where it's produced by a heat-driven chemical reaction. In solid form, it turns up in a pair of common cyanide salts - sodium cyanide (NaCN) and potassium cyanide (KCN). These compounds are used in industrial processes, mostly in metal industries from extraction to electroplating to polishing. And they are tend to be part of the standard chemical catalog in research laboratories at both universities and pharmaceutical companies.

Which brings us back to Dr. Klein. Doctors working at research hospitals are far more likely have access to this poison than you or I. They would also know its potency - in a dose of 200 or so milligrams (an amount you easily pack into an aspirin-sized pill - cyanide salts can kill in a matter of minutes. The Medscape reference on cyanide notesthat: "Cyanides are also used as suicidal agents, particularly among health care and laboratory workers.

But there's no evidence that Dr. Klein, a rising star scientist, a loving mother to a 6-year-old daughter, was suicidal. Her parents have stated that publicly. As a result, the police investigation - with help from the FBI - has broadened to also consider everything from accident to homicide. Detectives have searched home of Klein and her husband, Dr. Robert Ferrante, a researcher at the University of Pittsburgh. They also searched Ferrante's office and issued to subpoenas to both the hospital and the university, tracking in particular the research use of cyanide.

All of this is standard investigation following a suspicious death. No charges or accusations have been made; the police have made no statements implicating a suspect. Ferrante has proactively hired an attorney and a high-powered forensic pathologist. He also had the body cremated, a decision that his expert, Dr. Cyril Wecht, called "unfortunate" in a recent interview.

Why? Because blood tests are not always reliable (cyanide levels can change according to age, storage, handling of the blood). And because a thorough autopsy could have provided much more detailed information about the type of poison used - for instance, potassium and sodium cyanide tend to be corrosive when swallowed, can damage the lining of the stomach. And that kind of finding could be helpful in determining the precise poison used, the method of intake, - and for confirming - or possibly refusing - the blood test results, in solving the mystery.

It's the lethal puzzle, as much as the poison, that's drawn so much attention to this case, cased the networks to swarm, as one news story put it, caused ABC News to describe it as "the mystery that has everyone guessing." The cyanides are wonderfully potent compounds, poisons with a long dark history. But we're the ones who've built that history and it's what we choose to do with them that makes the tales worth telling.

And that knowledge adds to our wish for answers and for justice in the matter of Autumn Marie Klein.

Images:1) University of Pittsburgh Medical Center/Wikimedia Commons/Piotrus 2) UMPC staff photo of Autumn Marie Klein/Pittsburgh Post-Gazette