Beating the Devil's Game: A History of Forensic Science and Criminal by Katherine Ramsland

detectives escort to Washington; Warne posed as an invalid to stay close to him and watch for assassination attempts. She became one of the top agents in the agency, taking command of an all-female unit, but died young, with Pinkerton at her side. It was a sore loss for the man who’d initially been skeptical.
    “The Eye,” as Pinkerton came to be known, developed a reputation for solid integrity and delivery of services. His company motto was, “We never sleep,” and he eagerly set up undercover operations, espionage for the government, and an interstate cleanup operation of the West’s notorious bandits and gangs. Unfortunately, the Chicago fire of 1871 destroyed the impressive Pinkerton archive of documents and daguerreotypes, and the great detective himself died in 1884, although the agency continued his legacy.
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    In France, affairs among the famous brought attention to the microscope. The duc de Choiseul-Praslin, Charles-Louis Theobald, had married the daughter of one of Napoleon’s generals. Her name was Fanny, and she bore him nine children. They hired Henriette Deluzy as a governess and the duke began an affair with her. Fanny fired her but Charles-Louis publicly continued seeing her, so Fanny announced she would seek a divorce. Shortly afterward, on August 17, 1847, the servants heard a scream from Fanny’s bedroom, amid the crashing of furniture. They believed a burglary was in process, but her locked doors hindered them from entering. From outside in the garden, they could see Charles-Louis framed in the window, so they returned to the room, which was now open. Fanny had been beaten to death with a blunt instrument and her throat was slashed open. Charles ran in and acted as if he’d only just discovered his murdered wife that moment. Since the servants had been unable to get into the room until after they saw him there, his story clearly had holes.
    M. Allard, Vidocq’s successor to the head of the
Sûreté
, surmised at once that the duke was lying. There was no evidence of a burglary and a pistol found under the bed belonged to him. It was covered in blood, as if used to bludgeon the victim. Charles-Louis claimed that he had run into the room with it, but seeing Fanny already dead, had dropped the gun to hold her. When he saw he couldn’t help her, he went back to his room to wash off the blood, and a blood trail attested to that. The problem was, did he return to his room after killing her or after discovering her? In his room was a blood-stained dagger and the severed blood-stained cord from his wife’s bellpull, which the servants had heard when the victim first screamed for help.
    Allard arrested Charles-Louis and then set about trying to disprove the story he told. For assistance, he invited pathologist Ambroise Tardieu to observe the scene and the body. Tardieu had gained eminence with his study of asphyxiation victims, noting the differences among those who hanged or were suffocated by strangulation, chest pressure, or smothering. He even called the spots of blood that formed under the heart during rapid suffocation “Tardieu spots,” after himself.
    He examined the pistol under a microscope and located a chestnut-colored hair on its butt (the victim’s hair color) and skin fragments near the trigger guard. In addition, the wounds on the duchess’s head matched the size of the pistol butt. This evidence undermined the duke’s story. Tardieu’s reconstruction was that Charles-Louis entered his wife’s room to slit her throat, but failing this, bludgeoned her to death as she screamed and fought. Her struggle seemed affirmed by a fresh bite mark on the duke’s leg, which seemed to match his late wife’s teeth.
    However, Charles-Louis apparently realized that his story wouldn’t hold up and he poisoned himself with arsenic.
    MID-CENTURY PROGRESS
    Trial judges were showing a more tolerant attitude toward physicians and other scientists. Throughout America, societies of medical