Famed pathologist: Can't tell if Dr. Autumn Klein was poisoned

PITTSBURGH - A renowned pathologist says he could not determine whether neurologist Autumn Klein was fatally poisoned by her husband, a University of Pittsburgh medical researcher on trial for criminal homicide.

Dr. Cyril Wecht testified Wednesday that he reached that conclusion based on conflicting blood test results and evidence that Dr. Klein's death could have been due to another cause, such as a heart problem.

"You've got a mixed batch and that's what leads me at this point and today to the conclusion that it's undetermined," Wecht said, when asked about the cause and manner of Klein's death.

Wecht was among the last defense witnesses being called Wednesday, the 10th day of testimony in the trial of Dr. Robert Ferrante, 66.

Allegheny County prosecutors say Ferrante laced his 41-year-old wife's energy drink with cyanide in April 2013, moments before she fell suddenly ill in their kitchen. She died three days later.

Previous testimony has suggested Klein was pressuring Ferrante to have another child - the couple, married in 2001, had a 6-year-old daughter when Klein died - and that Ferrante had texted Klein to suggest the energy drink might help them conceive. Other testimony showed someone used Ferrante's computers to search for information on cyanide poisoning in the weeks before Klein died and, after she died but before he was arrested, on how a coroner might detect the poison.

The defense called Wecht to counter blood test evidence and a prosecution expert's testimony that Klein was poisoned.

A test done by Quest Diagnostics on blood drawn from Klein hours after she collapsed in her home showed a lethal level of cyanide. But that result wasn't known to investigators until after Klein was dead and her body cremated.

A county crime lab test also confirmed cyanide in Klein's blood, but not a specific level.

The medical examiner's office then sent another blood sample to NMS Labs, which couldn't test the blood because of an equipment malfunction and because a calibrating experiment indicated another testing method wasn't reliable. NMS eventually found a cyanide metabolite - a substance created when the poison is broken down in the bloodstream - but only at a level that could normally occur in a person's blood.

Wecht said the disparity between the Quest and NMS results left him unable to definitively determine the cause and manner of Klein's death.

"One would lead me to determine it's a homicide," Wecht said, "while the other leads me to believe it was a natural death."

Wecht, who served two separate 10-year terms as county coroner, is well known in the Pittsburgh area and is a "forensic celebrity," having consulted on the deaths of JonBenet Ramsey and Elvis Presley, among others. He first gained widespread fame as a critic of the Warren Commission's conclusion that Lee Harvey Oswald alone assassinated President John F. Kennedy in 1963.

The prosecution's main expert, a University of Virginia professor who wrote a book on criminal poisoning, Dr. Christopher Holstege, previously discounted the possibility that Klein died from a heart arrhythmia or some other sudden, unexplained cause because he said the evidence for other causes was lacking.

Wecht said he couldn't rule out natural causes because of what he considers conflicting blood test results.

"That's the basis for my opinion," Wecht said. "I'm stuck. I'm intellectually stuck."

The defense expected to briefly call some more witnesses before resting Wednesday. Closing arguments were expected Thursday, after which the jury will be sequestered until a verdict.

The prosecution is seeking a first-degree murder conviction, which carries a mandatory life prison sentence.