Crime Library: Criminal Minds and Methods

Forensic Toxicology

A Very Cold Case

Portrait of Dr. Emil Bessels
Portrait of Dr. Emil Bessels
 

In 1871, Charles Francis Hall led an expedition in search of the North Pole, supported with a sizable grant from the U.S. Congress.   Hall was experienced in arctic conditions, but not with a haughty crew member, physician and chief scientist Dr. Emil Bessels.  They set anchor for the winter about 500 miles from their goal in a harbor at Greenland.  Bessels and another officer insisted that they go south for safety.  Hall stood firm on his plans.

On October 24, after drinking coffee, Hall became ill.   Bessels gave him medications, but he only grew worse.  He believed he was being poisoned, but before anyone could do anything for him, he died on November 8.  The crew buried him in Greenland.  Later after an inquiry, it was determined that Captain Hall had died from natural causes.

The case seemed to be closed, but people remained curious.   It was nearly a century before another scientist decided to find out if Hall might actually have been poisoned.  Over time, scientists had learned that human hair roots absorb arsenic like blotting paper and each dose leaves a permanent and measurable record in every growing strand.  If someone dies from arsenic poisoning, there should be a high concentration close to the roots.  Fingernails will also provide a record via growth patterns.

Professor Chauncey C. Loomis of Dartmouth College and pathologist Dr. Franklin Paddock formed a team and went to Greenland to exhume Hall's remains.  They performed an autopsy right there on the ground, because the coffin was frozen into the earth and the body with it.  But it was remarkably well-preserved.  Hall's body fat had been converted into adipocere, a substance like soap that had a preservative effect on the internal organs.  That was good news for the scientists.

They removed various samples from strategic places, including hair samples and fingernails.  They also took samples from the soil surrounding the coffin.  They subjected all of this to a modern technique called neutron activation analysis.

Using neutron activation analysis, a specimen is placed in a nuclear reactor and irradiated with a stream of neutrons.   It then becomes destabilized in terms of the ratio of protons to neutrons in the sample's atoms and becomes radioactive, emitting gamma rays of a characteristic radiation level.  The rays are then measured in a spectrometer, and the treatment allows the scientist to measure even the sample's smallest constituent particles and identify the separate elements.  If a person ingested arsenic, the procedure separates it into its component parts and makes it possible to measure how much was ingested over the course of just a few days. 

To the scientists' disappointment, the Greenland soil samples contained a high percentage of arsenic.  Yet they could still learn things from the body that could indicate murder.

In Hall's fingernail, they found evidence that he had received a large amount of arsenic during the last two weeks before his death.   Since the nail had shown differential growth, its condition stood against the idea that arsenic had leached through the coffin into the body.  The hair samples displayed the same thing.  Had the arsenic come from the soil, the distribution would have been more uniform.  Given Hall's reported symptoms, his suspicions, and the results of the analysis with modern forensic technology, those involved in the investigation agreed that the chances were good that Hall had been murdered.

Yet even with the likelihood of murder, there was no telling who the murderer was.   Several people had been at odds with Hall.  Despite the obvious suspect, there was no evidence tying Bessels to the crime.

In a similar case, what seemed obvious from the body samples became less certain with new information.

 

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