Ancient Cases and Mysteries (World of Forensic Science)
Modern forensic science has provided historians, archeologists, and anthropologists with new tools to investigate mysteries whose roots extend back hundreds, even thousands, of years. DNA analysis, for example, has shed light on such cases as that of the Peruvian Ice Maiden, the 500-year-old mummified body of a young girl sacrificed to the gods by Incan priests, discovered in 1995. It has also identified with certainty the skeletal remains of the Romanovs, the Russian royal family killed by revolutionaries in 1918. In 2005 Spanish researchers hope to use DNA analysis to settle a dispute over whether the remains of explorer Christopher Columbus are buried in Spain or the Dominican Republic.
Forensic scientists have unlocked the secrets of human remains, such as the mummy of ancient Egyptian king Tutankhamen. The discovery of King Tut and his tomb in 1922 was the most significant archeological find of its generation. The burial chamber, which had survived intact for over 3,000 years, was filled with gold, ivory, and carved wooden treasures, including a now-famous funerary mask. But some features of the tomb puzzled archeologists. The burial chamber's small size suggested that it was built for a non-royal. It appeared to be unfinished and to have been hastily decorated, with paintings marred by splotches of paint that were never cleaned up. The tomb's artifacts were originally marked with other people's names, which were rubbed out and replaced with Tut's name. These features suggested that King Tut, who died at the early age of eighteen and who was the son of a controversial, and by some, hated, leader, may have died unexpectedly and of unnatural causes. Further, buckets of unguents dumped over the mummy raise the question of whether an attempt was made to cover up a murder.
In 1968 researchers from the University of Liverpool x-rayed the King Tut mummy and found a sliver of bone in the brain cavity and an area at the base of the skull that may have been a blood clot, clues suggesting that the king may have died from a lethal blow to the back of his head. Later, medical experts examined the x rays and spotted more clues. They found abnormalities in the bones above the king's eye sockets, consistent with injuries that occur when a head strikes the ground sharply in a backward fall and the brain snaps forward. Additionally, the vertebrae in the king's neck were fused, evidence of a condition called Klippel-Fell syndrome that makes a person highly susceptible to serious injury from a fall or a push. If Tut was murdered, suspects include Maya, his royal treasurer; Horemheb, his military commander; Ankhesenamen, his wife; and Ay, his prime minister, who assumed the throne after Tut's death. Additional forensic evidence was gathered in 2005, when Tut's mummy was removed from his tomb and scanned in a CT scanner. The resulting evidence may never solve the crime, but it may establish whether or not a crime took place. In March 2005, scientists were also considering the possibility that Tutankhamen could have died from complications of a fracture, when the CT results revealed evidence of a broken left thighbone.
Other forensic scientists focus not only on a body, but also on the physical environment in which a historical person died, searching for clues as to the cause of death. Such is the case with French emperor Napoleon, who in October 1815, after the Battle of Waterloo, was exiled by the British to the island of Saint Helena, where he died on May 5, 1821. The official cause of death was listed as a perforated stomach ulcer that had turned cancerous. In 1955 though, the diaries of his valet, Louis Marchand, were published. Marchand's descriptions of the emperor and his behavior in the months before his death created suspicion that he had been poisoned to death with arsenic administered over a long period of time.
In 2001 the Strasbourg Forensic Institute in France bolstered this suspicion by examining a lock of the emperor's hair. Arsenic, usually in the form of white arsenic, or arsenic oxide, works as a poison by binding with sulfur atoms in proteins and enzymes, interfering with their ability to regulate body chemistry. The protein keratin, found in hair, contains sulfur atoms, so evidence of arsenic poisoning will survive in the hair. What's more, because hair grows, a histogram of segments of the hair, created by subjecting the hair sample to x-ray fluorescence spectroscopy, can show how arsenic levels changed over time. The Strasbourg researchers concluded that during the time in which the sample of hair grew, Napoleon's body contained arsenic concentrations of seven to thirty-eight times higher than normal.
The central question is: Was Napoleon deliberately poisoned to death, perhaps by his captors, by a disgruntled staff member, or by French Bourbons who wanted to ensure that he never resumed the throne? Some researchers say no. The head of the toxicology department for the Paris police noted that hair samples from 1805 and 1814 show similar concentrations of arsenic. If arsenic had caused the emperor's death, he would have died much earlier. Further, arsenic was at the time a common ingredient in some medicines and in hair tonics.
In the nineteenth century, mysterious cases of arsenic poisoning were turning up in Europe, but it was not until 1893 that an Italian chemist named E. Gosio worked out what was happening: that when wallpaper containing a particular pigment became damp and moldy, the mold converted a compound in
Forensic investigation has also proven useful in authenticating or disproving claims made about artifacts. One is the Shroud of Turin, a 14-by-3 1/2-foot (4.27-by-1-meter) bloodstained burial cloth that shows faint images of a man who appears to have been tortured and crucified. The cloth came to light in 1204, when the Crusaders sacked the city of Constantinople. The cloth had been removed from the Middle Eastern city of Edessa in 944, where it had been discovered in 544. It was displayed in Lirey, France, in the 1350s but later moved to Chambery, France, where it was almost destroyed by fire in 1532. Many scientists assert that the Edessa Cloth and what is today called the Shroud of Turin (in Turin, Italy) are one and the same. Many people believe that the shroud is the burial cloth of Jesus Christ and that the images are his; some believe that the images are the product of a miracle.
The Shroud of Turin has intrigued modern forensic scientists, especially chemists, whose central question is whether the shroud could have been Christ's burial shroudhat is, whether it was a Greco-Roman burial shroud that can be placed in Jerusalem two thousand years ago. The nature of the cloth, the presence of travertine aragonite limestone dirt particles on it, and pollen grains, some from species now extinct, support claims that the shroud was in the environs of Jerusalem. In 1988 carbon-14 dating apparently proved that the cloth dated from the medieval period, and was hence a fake. More recent studies insist that the carbon-14 sample used in those tests was invalid, contaminated by a later repair patch, and that the cloth dates from an earlier century. The image shows coins on the man's eyes, a common burial practice at the time, and evidence suggests that the coins were struck during the first century A.D.
Scientists have also probed the images on the cloth, subjecting them to a panoply of scientific tests, including visible and ultraviolet spectrometry, infrared spectrometry, x-ray fluorescence spectrometry, thermography, pyrolysis-mass-spectrometry, lasermicroprobe analyses, and microchemical testing. Such tests reveal that the images were not formed by dyes or pigments, meaning that they were not somehow "painted" onto the cloth. Rather, the images are superficial (20000 nanometers thick) and fully contained in a layer of starch and saccharides (simple sugars) coating the outermost layers of the fabric. Further, a faint image on the reverse side of the cloth corresponds exactly with the image on the outside. Analysis shows that this image, too, is superficial, meaning that nothing soaked through the cloth from the inside to form the image on the outside. The color, often described as caramel-like, was likely the result of a complex chemical reaction, called a Maillard reaction, between amines, or ammonia derivatives, that are released by decaying bodies, and saccharides in a carbohydrate residue covering the fibers of the shroud and likely originating with soap that was used to clean the cloth. Put simply, the images appear to have a natural explanation and are not the result of fakery. Despite these tests, the debate continues, and the Shroud of Turin remains a chief exhibit in the debate between faith and science.
SEE ALSO Infrared detection devices; Mummies; Paint analysis; Peruvian Ice Maiden; Skeletal analysis; Spectroscopy.