The Science of Sherlock Holmes: From Baskerville Hall to the Valley of Fear, the Real Forensics Behind the Great Detective's Greatest Cases

by E. J. Wagner

  Dr. Henry Letheby testified concerning the blood evidence. He had not examined the bloodstained scene until July 26, and the walking stick was not subjected to his scrutiny until October 6. By that time, the stains were dried and hard to identify. The issue was important because the position and shape of the blood spots and stains would aid Letheby in reconstructing the crime.

  Holmes relies on similar evidence in “The Adventure of the Bruce Partington Plans,” saying to Watson, “Either the body fell from the roof, or a very curious coincidence has occurred. But now consider the question of the blood. Of course, there was no bleeding on the line if the body had bled elsewhere. Each fact is suggestive in itself. Together they have a cumulative force.”

  Dr. Letheby used several techniques to determine which spots were blood. He testified:

  I have measured the globules of blood, and I believe it to be human blood… . There was blood on the glass… . It had the characteristics of human blood, and, from the coagulum in it, had been living when it came on the glass. It contained particles of brain matter. There were two spots like splashes. They were about the size of sixpences. Such an effect would have been produced by a blow if a person had been sitting on that part of the carriage and had been struck on the left side of the head; as he was leaning against the glass that effect might have been produced.

  Dr. Letheby stated, “I used a microscope [as we gather from Dr. Letheby’s notes, which were inherited by Dr. Tidy, a spectroscope was attached to the microscope] and also chemical tests to determine the character of the stains.”

  No doubt it was the desiccated quality of the stains that prompted the chemist to include the use of the spectroscope in his arsenal of tests. He relied on a technique that had a venerable past. Some of the early experiments were done by a maker of lenses and physicist named Joseph von Fraunhofer. Leaning on the previous work of Isaac Newton and William Wollaston, among others, Fraunhofer, in the early part of the nineteenth century, constructed a device composed of a lens, a prism, and a small telescope. He placed these in front of a window shade that had a slit through which light passed. The light then traveled through the lens and prism and was examined through the telescope. Fraunhofer observed not only separated bands of color but dark lines running among them. Although the lens maker’s interest lay in understanding color rather than criminal science, he inadvertently made a great contribution to the latter. The dark lines he observed, now known as Fraunhofer lines, provided the idea.

  In 1859, Robert Wilhelm von Bunsen, professor of chemistry at Heidelberg (the very man credited with the invention of the Bunsen burner often used by Holmes), and his colleague, the physicist Gustav Robert Kirchoff, attached the spectroscope to a microscope and developed a highly accurate method of detecting hemoglobin. Henry Chapman, a nineteenthcentury American pathologist, described the concept:

  The spectroscopic method of investigating bloodstains is based on the fact that blood interferes with the transmission of certain rays of light, and that it gives rise to what are known as the dark absorption bands of the blood spectrum… . [W]hen light is transmitted through a prism it is decomposed into the seven colors: Violet, indigo, blue, green, yellow, orange, red. If, however, a weak solution of … blood be placed between the source of light and the prism, dark bands will appear [their location depending on whether the blood is venous or arterial].

  Another advocate of the method was Alfred Swaine Taylor, who explained:

  We simply examine the light as it traverses a solution of the red coloring matter, and with a proper spectral eyepiece attached to a microscope we notice whether the colored spectrum has undergone any change. If the red liquid owes its color to recent or oxidized blood, two dark absorption bands will be seen breaking the continuity of the colored spectrum. These are situated respectively at the junction of the yellow with the green rays, and in the middle of the green rays. If the blood is quite recent and of a bright red color the two absorption bands are distinct and well defined.

  Spectral analysis was highly sensitive and could detect blood in stains that were years old. While other substances such as dark red dyes could produce dark lines, they did not appear in the same place in the spectrum. The technique took great skill, but it worked very well.

  In his testimony in the Müller case, Dr. Letheby had been definite as to the location of the bloodstains and had provided a vivid word picture of how Mr. Briggs met his death. The jury found Franz Müller guilty, and he was publicly hanged outside of Newgate Prison in November 1864.

  The Müller case influenced a number of changes in England. The dangerous isolation of train passengers was mitigated by the installation of small windows in the front and back of railway carriages—these were sometimes referred to as “Muller lights.” The Regulation of Railways Act required the installation of communication cords on trains by 1868. The victim’s top hat that Müller had cut down sparked a dashing new fashion among stylish young men, affording the executed man a sartorial remembrance.

  In the forensic world, the spectroscope grew in importance, but it was not universally put to use. Information as well as technical training spread slowly in those days. Although Alfred Swaine Taylor was arguing in 1873 that if a “well-trained person skilled in micro-spectral observations” used the method, the “minutest traces of blood would be disclosed,” we find a number of historically important cases in which only older, less sensitive techniques were relied on.

  The case of the infamous Borden murders in Fall River, Massachusetts, provides a glimpse into the approach toward blood evidence in 1892 New England courtrooms. The Borden family lived discordantly in a narrow, inconveniently constructed house on Second Street. The household consisted of seventy-year-old Andrew Borden, a former undertaker who was currently a successful but compulsively frugal businessman; his two daughters from his first marriage—Emma, who was forty-two, and Lizzie, ten years Emma’s junior; and Abby Borden, Andrew’s second wife, who was sixty-four. A maid named Bridget lived with them; she was referred to by the family as Maggie, since the previous maid had been called Maggie, and it evidently required too much effort of the Bordens to change the name by which they addressed their servant.

  The Borden daughters bitterly resented their stepmother, to the point where they declined to dine with her and referred to her as Mrs. Borden. Suspicion simmered among the family members—upset stomachs gave rise to talk of poison; missing items from Mrs. Borden’s bedroom resulted in interior doors being locked. On the steaming hot day of August 4, 1892, Emma was out of town visiting friends. The elder Bordens, who with Maggie were recovering from a bout of intestinal problems, breakfasted unpleasantly on reheated mutton soup, bananas, and coffee. Lizzie, rising later, sipped only coffee. Mrs. Borden went upstairs to change the bed linen; Mr. Borden went into town on business; Maggie washed the windows between bouts of nausea.

  By ten forty-five, Mr. Borden returned home and stretched out on the parlor sofa to nap. Maggie went up to her stifling attic room to do the same. At about eleven o’clock, Maggie was startled by a cry from Lizzie on the ground floor.

  “Maggie—come down here! Father’s dead! Somebody’s come in and killed him!”

  Lizzie was not exaggerating. Mr. Borden lay on the sofa, his head bleeding profusely. One eye dangled from its socket, and his nose was severed. He had been struck in the face at least eleven times, and fresh blood still ran from the wounds. The doctor and a neighbor were sent for. After a quick examination of the corpse, the doctor covered it with a sheet.

  Lizzie had told Maggie that Mrs. Borden had, in response to a note, gone out to visit an unnamed sick person in town, but that Lizzie thought she had since heard her stepmother return. The neighbor and Maggie went upstairs to investigate and found Mrs. Borden on the floor of the guest room, her head crushed by repeated blows from an axe or a hatchet. The dead woman lay face down in a large pool of congealing and drying blood.

  Lizzie delivered herself of a number of contradictory statements about
where she had been during the crucial time. A local pharmacist informed police that the day before the murders he had refused Lizzie’s request to sell her prussic acid, which she claimed she wanted to preserve a fur cape. As Lizzie was the only person with both motive (she stood to inherit her father’s estate) and opportunity to commit the crime, she became a person of interest to the police.

  Had Lizzie, they wondered, expressed her displeasure with her parsimonious father and inconvenient stepmother by dispatching them with a hatchet? Medical opinion was that Mrs. Borden had died at least an hour before her husband. Was it possible that respectable, churchgoing Lizzie Borden had crouched on the stairs of that narrow house (which must have been still redolent of mutton soup and blood) waiting for her father to come home to a violent death? There was a great deal of evidence that she had, and to the shock of Fall River, the wellborn Lizzie Borden stood trial for the double murder.

  It is not our purpose here to savor all of the dark delights of the Borden mystery—it is the voice in the blood that is our current concern. So we will only mention the first, hasty autopsy, which was performed on the dining room table, chez Borden. (Home autopsies were still common at the time. It is probable that the table was protected by undertaker’s boards during the operation, which makes the exercise much more palatable.)

  The second, more thorough postmortem was performed alfresco at the grave site following the service, after the mourners had taken their sorrowful leave. As this occurred a week after the murders, the bodies were somewhat decomposed, but the open air made the odor tolerable, and there was sufficient light for a series of photographs to be taken. The heads were removed, to be stripped of their flesh, the better to disclose the horrendous wounds they bore when they were exhibited in court.

  At trial, the blood was a subject of much importance. Which stains at the scene were blood and which were not? Where blood had fallen and where it hadn’t, how fast it coagulated, and how slowly it dried were all at issue. Was the lack of visible blood on Lizzie the day of the murder evidence of innocence? Or was it evidence of guilt, as it could easily be argued that a loving daughter innocent of the assault would have approached her injured father and inevitably been stained with his blood? What was the weapon? And where was it now?

  William Dolan, the medical examiner for Bristol County, was one of the first at the scene. By an incredible coincidence, Dr. Dolan was walking past the Borden home at eleven forty-five, just after the discovery of the bodies. His testimony at the preliminary hearing and trial gives us an idea of how the physical evidence was evaluated:

  I have practiced medicine in Fall River for eleven years; received my education in the medical department of the University of Pennsylvania. I have been in general practice, with probably more surgery than medicine. Have had several cases of fracture of the skull. Have been medical examiner for Bristol County for two years; for one year, when these murders took place… .

  There was very little blood on his [Andrew Borden’s] clothing, except on his bosom, his shirt bosom, and of course the back where the blood ran down, that is, in the back of his cardigan, and his clothes were soaked, where it had run down from his face to the lounge, as it lay on the lounge… .

  There was not a great deal on the floor. It was dropping when I was there, dropping from the lounge in two places on to the carpet… .

  [Dolan then describes a number of separate blood spot clusters.] Taking first the wall behind the sofa, there were in one cluster of spots, as it were, radiating, describing the arc of a circle, there were seventy eight blood spots… .

  I believe there were eighty six spots. The highest of those of that particular cluster I think were three feet seven inches from the floor.

  Some very minute, some the size of a pin head, others were the size of a pea, and varying from that… . I then found on the paper above the head of the lounge, the highest spot except one upon the ceiling; that was six feet one and three quarters inches from the floor.

  Those spots, I did not exactly measure them [a great many details were not exactly measured by Dr. Dolan], but they must have been half an inch in their longest axis by quarter of an inch in width… .

  On that picture and frame were in all forty spots. The highest spot there was fifty eight inches from the floor… .

  I found the carpet underneath the head of the lounge in two spots two pools there of blood. I found on the parlor door west of the head of the lounge about seven drops, that is on the door and on the jamb.

  I think about five feet … I did not measure it accurately [again no measurement, no photograph, no diagram—Sherlock Holmes as well as Hans Gross would have been no doubt displeased] … one very large one in the center division of the upper two panels of the door… . The top one was quite a large one… . Taking the one I told you above the lounge as the biggest one, about half an inch in length, this would be about two-thirds the size of that… .

  We saw two spots upon the ceiling immediately above, not exactly above the head of the lounge. I do not think it was human blood; I think it was some insect that had been killed there. There was another spot … that was in all probability human [but he is not sure]… .

  It was not a spot; it was a string, as it were, of blood. Instead of being a spot of blood, that was long, it would probably measure, if drawn out, two inches or two and a half inches… .

  The one in the groove was a medium spot. I could not give you the measurement … it was probably the size of a huckleberry, a small huckleberry… .

  All the others were spots, were real spots, you could tell from the way they struck. They drew down just as a spot of water on a piece of paper would do where it struck. It made a larger spot and pressed downward and made a neck. The other one there was a line, without much width.

  It could be made by swinging from an instrument used in murdering Mr. Borden.

  It seems evident that Dr. Dolan was primarily concerned with the physical distribution of the blood. Even so, he did not make precise measurements, and the photographs taken at the scene are blurred and indistinct.

  Concerning the body of Mrs. Abby Borden, Dr. Dolan testified:

  Under her head, and pretty well down on her breast, she was lying in a pool of clotted blood, quite dark, as if it had been there sometime. It was not in the fluid condition that Mr. Borden’s was.

  The front of the clothing was very much soaked, that is, down to the chest, and also the back, down about half way, of course going right through to her underclothing.

  On the pillow sham, immediately above, about a foot or eighteen inches in front were about three spots. On the rail of the bed I should judge there would be from thirty to forty, probably fifty spots of blood.

  The medical testimony of a Dr. Edward Wood was presented:

  I am a physician and chemist—since 1876 professor of chemistry in the Harvard Medical School. Have given special attention to medical chemistry, to medicolegal cases, involving poisons and bloodstains. Have been called upon in several hundred trials, including a large number of capital cases.

  Dr. Wood then testified that he had examined the stomachs and intestines of the victims, had found them to be normal, and could locate no sign of poison. We should recall, however, that a chemist will find only the poison he suspects and specifically tests for. Dr. Wood’s testimony does not report tests for any other drugs or sedatives—a dose of which might have accounted for the nausea and sleepiness of the Borden ménage.

  Dr. Wood’s testimony continued:

  On August 10, at Fall River, I received from Dr. Dolan the large hatchet known as the claw-hammer hatchet; the two axes; the blue-dress skirt and waist; the white skirt [Lizzie’s clothing]; the sitting-room carpet; the bedroom carpet; … three small envelopes, one labeled “hair of Mrs. Borden, 8/7/92, 12.10 P.M.,” one labeled “hair from A. J. Borden, 8/7/92, 12.14 P.M.,” one labeled “hair taken from the hatchet.”

  The claw-hammer hatchet had several stains on it which appeared like bloodstains, on
handle, side and edge. All the stains on the head of the hatchet were subjected by me to chemical and microscopic tests for blood, and with absolutely negative results. The two axes, which I designated A and B, had stains which appeared like blood, but tests showed them absolutely free from blood. [The hairs, he said, were most likely cow’s.] …

  The blue skirt has, near the pocket, a brownish smooch, which resembled blood, but a test showed it was not. [The test is not specified, and no question concerning this is raised. Lack of detailed questioning of expert witnesses on scientific matters is common in this period.] Another, lower down, proved not to be blood. The waist had not even a suspicion of bloodstain. The white skirt had a small blood spot, six inches from the bottom of the skirt. It was 1⁄16 inch in diameter: the size of the head of a small pin. The corpuscles, examined under a high-power microscope, averaged 1⁄3243 of an inch, and it is therefore consistent with its being human blood. Some animals show a similar measurement: the seal, the opossum and one variety of guinea pig. The rabbit and the dog come pretty near. [Dr. Wood mentions the measurements of the corpuscles but does not mention spectrum analysis.] …

  Experiments which I made with the two carpets, from the sitting room and the guest chamber, showed that blood dried on them with equal rapidity… .

  There is the small hatchet, which I should have mentioned in connection with the claw-hammer hatchet. The latter has a cutting edge of 41⁄2 inches; the small one an edge of 31⁄8 inches… .

  Q. I will ask you the same question I did with reference to the other hatchet, whether in your opinion that hatchet could have been used and then cleaned in any manner so as to remove any trace of blood beyond the power of your discovery, as you examined it?

  A. It couldn’t have been done by a quick washing. Q. Why not?

  A. It would cling in those angles there and couldn’t be

  thoroughly removed. The coagula would cling. It would have to be very thoroughly washed in order to remove it. It could be done by cold water, no question about that. But it couldn’t be done by a careless washing… .