The Ripper's victims would have been a forensic nightmare because of the contamination and mixture of trace evidence - including seminal fluid - from multiple clients, all of it exacerbated by the women's pitiful hygiene. But there would have been some substance, organic or inorganic, worth collecting. Unusual evidence may very well have been discovered. Cosmetics worn by a killer are easily transferred to a victim. Had Sickert applied grease paint to darken his skin, had he temporarily dyed his hair, or had he been wearing adhesives for false mustaches and beards, these substances could be discovered by using a polarized light microscope or chemical analysis or spectrophotofluorometric methods, such as the Omnichrome light, that are available to forensic scientists today.
Some dyes in lipsticks are so easily identifiable by scientific methods that it is possible to determine the brand and trade name of the color. Sickert's grease paints and paints from his studio would not have eluded the scanning electron microscope, the ion microprobe, the x-ray diffractometer, or thin-layer chromatography, to list a few of the resources available now. Tempera paint on a 1920s Sickert painting titled Broad-stairs lit up a neon blue when we examined it with a nondestructive alternate light source at the Virginia Institute of Forensic Science and Medicine. If Sickert had transferred a microscopic residue of a similar tempera paint from his clothing or hands to a victim, the Omnichrome would have detected it and chemical analysis would have followed.
Finding an artist's paint on a murder victim would have been a significant break in the investigation. Had it been possible in the Victorian era to detect paints adhering to a victim's blood, the police might not have been so quick to assume Jack the Ripper was a butcher, a lunatic Pole or Russian Jew, or an insane medical student. The presence of residues consistent with cosmetics or adhesives would have raised significant questions as well. Stray knives turning up would have given answers instead of only posing questions.
A preliminary quick-and-easy chemical test could have determined whether the dried reddish material on the blades was blood instead of rust or some other substance. Precipitin tests that react to antibodies would have determined if the blood was human, and finally, DNA would either match a victim's genetic profile or not. It is possible that latent fingerprints could have been found on a knife. It is possible that the killer's DNA could have been determined had Jack the Ripper cut himself or perspired into the handkerchief he wrapped around a knife handle.
Hairs could be compared or analyzed for non-nuclear or mitochondrial DNA. Tool marks imparted by the weapon to cartilage or bone could have been compared to any weapon recovered. These days, all that could be done would be, but what we can't account for is how much Sickert would know were he committing his murders now. He was described by acquaintances as having a scientific mind. His paintings and etchings demonstrate considerable technical skill.
He did some of his drawings in a tradesman's day book that had columns for pounds, shillings, and pence. On the backs of other drawings are mathematical scribbles, perhaps from Sickert's calculating the prices of things. These same sorts of scribbles are on a scrap of lined paper the Ripper wrote a letter on. Apparently he was figuring out the price of coal.
Sickert's art was premeditated and so were his crimes. I strongly suspect he would know about today's forensic science, were he committing his murders now, just as he knew what was available in 1888, which was handwriting comparison, identification by physical features, and "fingermarks." He also would have been keenly aware of sexually transmitted diseases, and it is likely he exposed himself to his victims' body fluids as little as possible. He may have worn gloves when he killed and then removed his bloody clothing as quickly as he could. He may have worn rubber-soled boots that were quiet on the street and easy to clean. He could have carried changes of clothing, disguises, and weapons in a Gladstone bag. He could have wrapped items in newspaper and string.
The day after Mary Ann Nichols's murder, Saturday, September 1st, the Daily Telegraph and the Weekly Dispatch ran stories about the peculiar experience a dairyman claimed to have had at 11:00 P.M. the night before, or within hours of Mary Ann's murder. The dairyman's shop was in Little Turner Street, off Commercial Road, and he reported to police that a stranger carrying a shiny black bag came to the door and asked to buy a penny's worth of milk, which he drank in one gulp.
He then asked to borrow the dairyman's shed for a moment, and while the stranger was inside it, the dairyman noticed a flash of white. He went to investigate and caught the stranger covering his trousers with a "pair of white overalls, such as engineers wear." The stranger next snatched out a white jacket and quickly pulled it over his black cutaway as he said, "It's a dreadful murder, isn't it?" He grabbed his black bag and rushed into the street, exclaiming, "I think I have a clue!"
The dairyman described the stranger as about twenty-eight years old with a ruddy complexion, a three days' growth of beard, dark hair and large staring eyes, and as having the general appearance of a "clerk" or "student." The white coveralls and jacket - similar to what an "engineer" wore - were also what Sickert used to cover his clothing when he painted in his studios. Three sets of these white coveralls were donated by his second wife's family to the Tate Archive.
The dairyman's story takes on even more suspicious shadings when added to it is another account of clothing in the news after Elizabeth Stride's and Catherine Eddows's murders. The day following their murders, Monday, October 1st, at nine o'clock, a Mr. Chinn, who was the proprietor of Nelson Tavern in Kentish Town, discovered a newspaper-wrapped package behind the door of an outbuilding behind the tavern. He ignored the package until he happened to read about Elizabeth Stride's murder and realized that the package in his outbuilding matched the description of the one carried by a man who was seen talking to Elizabeth less than half an hour before her death.
Mr. Chinn went to the police station on Kentish Town Road to report the matter. When a detective arrived at the tavern, the package had been kicked into the roadway and had burst open. Inside was a pair of blood-soaked dark trousers. Hair was found adhering to coagulated bloodstains on the newspaper wrapping. No further description of the hair or newspaper wrapping seems to be known, and the trousers were subsequently carried off by a street person. I suppose the detective had no further use of them and simply left them in the road.
The description of the man carrying a newspaper-wrapped package whom Police Constable William Smith observed talking to Elizabeth Stride is similar to the description the dairyman gave police: Both men had a dark complexion, were clean-shaven - or at least had no full beard - and were approximately twenty-eight years old. The Nelson Tavern in Kentish Town was about two miles east of where Sickert lived in South Hampstead. He did not have a dark or weathered complexion, but it would have been easy enough for him to create one with makeup. He did not have dark hair. But actors wore wigs and dyed their hair.
It would have been a simple matter to leave wrapped packages or even Gladstone bags in hidden places, and it is doubtful that Sickert would have cared whether the police recovered a pair of bloody trousers. In those days, nothing useful could be learned from them unless they bore some sort of marking that could have been traced back to the owner.
Facial mutilations can be extremely revealing, and a forensic psychologist or profiler would assign great importance to the mutilation of Catherine Eddows's face, which, in Chief Inspector Donald Swanson's words, damaged her "almost beyond identity." The face is the person. To mutilate it is personal. Often this degree of violence occurs when the victim and assailant are known to each other, but not always. Sickert used to slash paintings to tatters when he decided to destroy his work. On one occasion he instructed his wife Ellen to go out and buy two curved, sharp knives that he said were just like ones she used for pruning.