Fingerprints: Murder and the Race to Uncover the Science of Identity

It is not the ridges’ function that makes them of interest to the identification expert, however. What fascinates him instead is the fact that the intricate ridge patterns are unique to each finger. A fingerprint expert can tell apart the marks of two digits more easily than he can differentiate two people’s faces. The facial features of identical twins, for example, can be mistaken, but their fingerprints can never be confused by a trained expert. A person’s fingerprint set is therefore a permanent and unmistakable record of his identity. It is like a biological seal which, once impressed, can never be denied. Eighty thousand such biological seals of convicted criminals crowded the pigeonholes in Scotland Yard’s fingerprint branch.

This massive collection of fingerprints, however, had never before been used to collar a murderer. Sleuthing was not the fingerprint expert’s primary function. Instead, Collins and his colleagues passed their days filing fingerprints taken from recent convicts and using the previously filed fingerprints to doublecheck the identities of the newly arrested. Their main goal was to identify “recidivist” or “habitual” offenders who pretended to be first-timers, adopting pseudonyms in hopes of hiding their previous convictions and getting lighter sentences.

The practice of correlating a criminal’s sentence with the number of his prior convictions began in the nineteenth century, when jail cells and prison guards first took the place of gallows and their hangmen. To the essentially honest man who fell on hard times and stole to feed his family, the new prison system prescribed a short stay behind bars, just enough unpleasantness to deter further crime. It was believed that the habitual offender, on the other hand, could not so easily have his criminal bent punished out of him. Long-term removal from society was thought to be the only way to prevent his misdeeds. There was one problem with this two-pronged penal approach: How do you tell the hardened criminals from the first-timers?

The first suggested use of fingerprints as a method of criminal identification came in an October 1880 issue of the prestigious scientific journal Nature. An article, penned by an unknown Scottish medical missionary working in Japan named Henry Faulds, proposed many of the elements of the fingerprint system as it eventually came to be used. Faulds, having studied thousands of fingerprints, would spend the next ten years trying to convince Scotland Yard to adopt the ideas in his article. The Yard dismissed Faulds as a crank, and cruelly, when it finally did adopt fingerprinting, denied that Faulds had any part in the system’s conception.

A month after the publication of Faulds’s article, a second article on fingerprints appeared, also in Nature. William Herschel, a British magistrate based in Bengal, replying to Faulds, wrote that he had used fingerprints officially as “sign-manuals,” or signatures, sanctioning the idea’s practicality. Still, the British establishment paid no attention to fingerprinting until, in 1888, the interest of the well-known scientist Francis Galton gave it credibility. A cousin of Charles Darwin, Galton’s passion was the improvement of the human race by artificial selection. He took to fingerprints, thinking their intricate ridge patterns might somehow reveal their owners’ physical and mental capacities—their worth as breeding stock.

Galton’s published work sparked the interest of the Inspector-General of Police in Bengal, India, Edward Henry, who made the leap from theory to practice and applied fingerprints to police work. Henry and his assistant, Azizul Hague, developed a classification system that allowed fingerprint sets to be logically filed according to the form of their ridge patterns. Without the system, an inspector searching for a particular fingerprint set would have to rummage through the entire collection. With it, he easily went straight to the place where the set was filed. What came to be known as the Henry classification system made possible the use of fingerprint registers numbering in the many thousands, a prerequisite for practical use in criminal identification.

When widespread use of fingerprint identification proved successful in India, Henry was in 1901 recalled to London, made Assistant Commissioner of the CID, and charged with establishing Scotland Yard’s new Fingerprint Branch. The branch had immediate success, cracking the pseudonyms of 632 repeat offenders in its first year. In 1905, Henry was promoted to Commissioner of Scotland Yard. He left the Fingerprint Branch in the hands of Detective-Inspector Charles Steadman and his deputy, Detective-Inspector Collins, the officer to whom Macnaghten delivered the Farrow murder cash box.

At his workbench, Collins examined the cash-box tray under his magnifying glass. Fingerprints can be impressed in anything from paint to blood, but this one, like most found at crime scenes, had been left in sweat. On the gripping surfaces of the hands and feet, 3,000 sweat glands per square inch crowd together more densely than anywhere else on the body. Keeping the skin lubricated so it does not crack, the glands also make each finger like a self-inking rubber stamp, leaving calling cards on every surface it touches.

Because of this, since most human action involves touching, fingerprints invisibly populate the world’s surfaces. Taken together, these fingerprints are like pages from the Recording Angel’s book of deeds, and Charles Collins, with his magnifying glass, could read them. If a fingerprint he found on an object matched a fingerprint in his cabinet, Collins could deduce the name of the person who touched the object. This is how Collins hoped to discover Farrow’s murderer.

The impression on the cash-box tray followed an arch pattern and came from a right thumb. Collins could tell that it was a thumb because the impression was too large to come from other fingers. He could tell right or left by the slope of the ridges. Ridge slope on a right thumb impression is more steep on its right side, and vice versa for a left thumb.

Collins’s next job was to search through his files, paying special attention to the prints of housebreakers who had an arch on the right thumb. He fingered his cabinet’s cards slowly and meticulously, for he knew that public acceptance of fingerprint evidence could be won through their successful use in this case. But no luck. On Tuesday morning, the day after the murder, he reluctantly reported to Macnaghten that the print on the cash-box tray did not match any prints on file.

The news was not all bad, however. Collins had compared the cash-box tray print to those of Mr. and Mrs. Farrow and of Sergeant Atkinson, who had mistakenly touched the tray. The print belonged to none of them. That meant that it probably belonged to one of the murderers. If so, Macnaghten and Collins thought they could use it to win both their case and their much desired public respect for fingerprints. But first a suspect had to be found.

The investigation’s first lucky break came when Chief Inspector Fox encountered Henry Jennings, a milkman, and Edward Russell, his eleven-year-old helper. During their rounds, about 7:15 on the morning of the murder, Jennings and Russell saw two men coming out of Chapman’s. One had a dark mustache and wore a blue suit, black boots, and a bowler hat. The other was clad in a dark brown suit, gray cap, and brown boots. Jennings shouted to them, “You have left the door open.” The mustached man turned around and said, “Oh! It is all right; it don’t matter,” and left the door ajar.

Fox now had descriptions of two suspects. But if the milkmen had last seen the door open at 7:15, and William Jones arrived at 8:30 to find it locked tight, who closed the door? Was there, Chief Inspector Fox wondered, a third robber who came out after the other two, closing the door behind him?

The fact that three masks had been found in the shop seemed to confirm this theory. Also, three men, two of them answering the descriptions given by the milkmen made a twenty-minute visit to Deptford’s Duke of Cambridge Pub at 6:00 A.M. on the morning of the murder. Could the third man in the pub have been the door-closer? The police took his description from the bartender and began searching for the third man, too.

Then police found another witness, Alfred Purfield, a painter. On the morning of the murder, he had waited for a colleague across the street from Chapman’s and watched the door being shut. It was “an old gentleman,” he told police. “He had blood on his face, shirt and hands. He stayed at the door for a short time and then closed it.” The door had been shut by Farrow himself. He had obviously regained consciousness one last time and, too dazed to call for help, simply closed the door before expiring in the parlor. This destroyed the third-man theory. Chief Inspector Fox was not happy. It was three days since the murder and he’d run out of leads.

Enter Fox’s second lucky break, a witness who took her time coming forward because she didn’t think what she saw was important. Ellen Stanton was on her way to catch the 7:20 train to London on the morning of the murder when she saw two men running from the High Street. What were they wearing? Fox asked. Stanton said one wore a dark suit and a dark cap and the other wore a bowler. Fox’s heart skipped a beat. Stanton was wrong about the importance of what she’d seen. Her description matched perfectly with the milkmen’s. Did you recognize them? Fox asked. “I recognize [sic] one of the men as Alfred Stratton. …” Stanton said. “I don’t know the man who was with him. …”

Suddenly, Fox had one suspect for sure and guessed he had another. Twenty-two-year-old Alfred Stratton’s younger brother Albert, twenty, was his constant cohort and he had a mustache to boot, matching the milkmen’s descriptions. The brothers had no criminal records, but they were known by the local police to be living off prostitutes. Fox reported all this to Macnaghten. The Strattons, Fox believed, were the culprits, but he lacked ironclad evidence. Macnaghten nevertheless ordered him to arrest the brothers. Once the Strattons were captured, Macnaghten reasoned, one of their thumbprints would provide all the evidence that was needed.

On Sunday night, six days after the murder, Alfred was arrested at the King of Prussia Pub in Deptford. The next morning, Albert was collared on a Deptford streetcorner. But at the police station, things took a nasty turn for Fox and Macnaghten when neither Jennings, the milkman, nor Russell, his helper, could pick the Stratton brothers out of a crowd of prisoners in the exercise yard. There would be no question, either, of identification by Mrs. Farrow; she had succumbed to her injuries and died. The Strattons, watching the police case fall apart, were so giddy with excitement that they joked that Detective-Inspector Collins tickled them when he took their fingerprints.

With no eyewitnesses linking the Strattons to Chapman’s, Macnaghten had to virtually beg the magistrate at Tower Bridge Police Court to remand the brothers into custody. He needed time, he explained, for Collins to compare their prints with the smudge on the cash box. The counsel from the public prosecutor’s office warned Macnaghten that the evidence in hand was insufficient for a prosecution. If the prints didn’t match, the brothers would go free.

Back in his office, Macnaghten waited impatiently for the results of Collins’s examination. Two tense hours passed as he pondered the press-lashing the Yard might take for another unsolved murder. Then Charles Collins rushed through his door, ecstatic. “Good God, sir,” he exclaimed, “I have found that the mark on the cash-box tray is in exact correspondence with the print of the right thumb of the elder prisoner.”

The Yard had its murderers. But knowing who committed a murder is a far cry from convicting him for it, especially in a tricky case like this one. No English jury had ever been asked to send men to the gallows on the basis of what was, after all, only a smudge of sweat. Prosecution was a gamble. If the case was lost, the Yard stood to take a considerable public hammering. On the other hand, winning could lead to public acceptance of the greatest crime-fighting tool of its time. Macnaghten deferred to Scotland Yard Commissioner Edward Henry to weigh the odds.

To its credit, fingerprinting had its four-year record of success in identifying habitual offenders. But the Fingerprint Branch had its detractors. Ten fingerprints may identify a man, believed a number of distinguished scientists and doctors, but they highly distrusted the use of a single fingerprint, especially when a hanging was at stake. So strong was their distrust that they would be willing to pit their reputations against Scotland Yard in any upcoming trial.

Most damaging among their mingled grumblings rang the voice of Henry Faulds, the man who first suggested fingerprints to identify criminals. Faulds had compared many thousands of fingerprint sets to satisfy himself that no ten fingerprints could be duplicated on two different people. He complained publicly that no one, including the Yard, had made a similar comparative study to prove that each single fingerprint was unique. Until this was done, he insisted, no man should be sent to the jailer or the hangman on the basis of a single fingerprint, particularly one identified by the Yard’s Fingerprint Branch. Ever since the Branch had denied Faulds’s part in the fingerprint conception, Faulds had bitterly questioned its integrity. It didn’t help the Yard’s case that Faulds delivered his arguments with the force of a man who had been scorned.

It didn’t help, either, that science didn’t have the foothold in the courtrooms that it does today. For most of history, the only evidence allowed at trial was the testimony of eyewitnesses. The use of physical evidence to reconstruct events had been considered too vulnerable to manipulation. The legal process had since been dragged slowly forward, but juries were still more used to hearing what people had seen with their own eyes than what experts said they could deduce by other means. Unlike the rest of society during the industrial revolution, the judiciary had not yet been won over by science. When he decided to take the gamble and prosecute the Stratton brothers for the murders of Thomas and Ann Farrow, Edward Henry knew that this trial could change all that. But the big question remained: Had thirteen hundred years of British legal history prepared the courts for one of their greatest-ever leaps into the future?

Two To Catch a Crook

In the commons of a sixth century village of what is now France, peasants crowded around a large cooking pot as if expecting a feast. Only boiling water filled the pot, though, and the only thing to feast upon would be a spectacle. Two arguing clergymen intended to plunge their unprotected arms elbow-deep into the scalding water. The idea was to settle a debate they’d had by conjuring supernatural “evidence” of God’s judgment. Presumably, the man with God on his side would be protected from the burning temperature.

The argument between the clergymen, a Catholic deacon and an Arian priest, was over the hierarchy of the Holy Trinity. The Catholic said that Christ and God were the same. The Arian insisted that the Son was inferior to the Father. This philosophical difference had caused the separation of their churches two centuries earlier, so in their hotheaded debate over this tired issue, neither clergyman was willing to budge from his original position. Finally, the Catholic deacon challenged the Arian priest to settle the issue in an “ordeal by boiling water.”

The priest and the deacon each spent a sleepless night on their knees in prayer, trying to curry God’s favor. The next day, they joined the crowd of curious peasants by the side of the cauldron. The flames beneath the pot leaping high, a ring was tossed through the clouding steam and into bubbling water. Each clergyman would take a turn fishing out the ring, and victory would go to whomever emerged from the trial least injured.

The Catholic deacon, feigning politeness, gestured his adversary forward for the first attempt. The Arian shook his head. The “privilege” of going first, he said, belonged with the challenger. Tentatively, the deacon stepped forward. He looked into the pot, hesitating. The ring whirled around violently. Catching it would be like trying to grab a piece of straw in a tornado. The Catholic slowly rolled up his sleeve, but his arm, the Arian immediately saw, was smeared with oil. Outraged, the Arian accused the Catholic of cheating. He declared the challenge void.

The Catholic deacon resigned from the ordeal, presumably with heartfelt relief. But the Arian was not off the hook. Another Catholic priest had stepped out of the crowd, insistent on taking the disgraced deacon’s place. The Arian’s back was against the wall. To refuse the new challenge, he would have to concede the issues of faith that had begun the fracas. Reluctantly, he examined the priest’s arm and, finding nothing to complain about, signaled him to proceed. The priest plunged his arm into the cauldron.

According to legend, the Catholic kept his arm submerged in the vigorously boiling water for two hours as he grasped for the ring. At last, he snatched it, raised it high above his head, and announced to onlookers that the water felt cold at the bottom and comfortably warm at the top. His hand and arm were miraculously uninjured. Emboldened by his adversary’s success, the Arian brazenly tossed the ring back into the water and thrust his own arm in after it. Within a moment, his flesh was boiled off the bone to his elbow. God apparently sided with the Catholic.

This kind of “non-rational evidence,” as historians would call it, settled every kind of community squabble in the Germanic tribes that overran Europe at that time. Even the fate of criminal suspects was at the mercy of the “trial by ordeal” in the Dark Ages. This judicial use of the ordeal was the great-grandfather of modern criminal proceedings. It was the first chapter in the history of the law of evidence, which would lead, more than a millennium later, to the use of fingerprints. But for now the law had no use for earthly clues. God knew who stole or killed, so gathering facts was irrelevant. Conjuring God’s judgment was the trial’s only goal.

In Saxon England, a frightened suspect often desperately tried to avoid the trial by ordeal by recruiting community members to swear to his good character, in the hope of convincing a judge to let the suspect off the hook. But since fire and brimstone would rain on compurgators who swore falsely, even the slightest scent of doubt in a suspect’s innocence meant his friends and acquaintances turned their backs on him. He’d have to admit guilt or submit to the ordeal, turning his fate over to what was, in essence, an elaborate coin toss.

The ordeal required prolonged contact of the accused criminal’s bare flesh with either boiling water or, just as commonly, a lump of red-hot iron. The worse the alleged crime, the deeper the judges made him plunge his hand into the boiling water, or the heavier the lump of red-hot iron they made him carry. The singed flesh was then sealed away in bandages. Three days later, judges examined the wounds and divined the evidence of God’s judgment. Healing meant innocence, release, and not so much as a muttered apology for the now crippled limb. The stench of infection indicated guilt and execution.

The ordeal was cruel and arbitrary, but it was better than the mass bloodshed that came with its alternative, vigilante justice. Then, a theft might lead to a fight, which ended in a killing, which was in turn avenged by a murder, which then sparked a clan war. The ordeal, at least, had the virtue of resolving conflict, in a procedure agreed by the community, before it devolved into blood feud. One innocent life might be sacrificed, but tens or hundreds were saved.

But ordeals and their ruthlessness long outlived the dangerous Dark Ages clan wars they were designed to prevent. One form of ordeal, the wager of battle, in which the accused and accuser, or their champions, pummeled each other with wooden staffs, remained common in England into the fifteenth century. If a defendant kept up the good fight from sunrise to sunset, he was innocent. Defeat once again fated him to the hanging tree. Even after this judicial jousting faded from practice, it lingered in the law books until it was resurrected for the last time, amazingly, in 1817.

On the morning of May 27 of that year, in Tyburn, near Birmingham, the dead body of a young woman named Mary Ashford was found at the bottom of a pit near her home. Abraham Thornton, a bricklayer and the son of a respectable builder, was arrested and tried for the murder. The jury found him not guilty. An archaic British law, however, allowed the appeal of a not guilty verdict in cases of murder, and Mary Ashford’s brother, wracked with grief over the death of his sister, instituted such an appeal. Thornton was again arrested.

If Mary Ashford’s brother could cite archaic law to bring this frivolous second trial against Thornton, his lawyers reasoned, then they could also invoke an obsolete statute. In court, they insisted that Abraham Thornton, a large and strong man, be allowed to answer the charges against him in a duel against his less physically robust accuser. The wager of battle, they maintained, had never been expunged from British law. After much quibbling between the lawyers, the judges came down on the side of Thornton. They ruled that if the trial were to continue, the brother would have to fight. Scared for his life, the brother withdrew his appeal, Thornton got his freedom, and both appeal of murder and wager of battle were struck, finally, from the English law books.

While the administration of justice relied on divining verdicts from God, methods as sophisticated as fingerprinting, and indeed any form of factual evidence, were a long way off. Developments were slow in coming. The old Saxon judicial system remained in use until in 1215 when Pope Innocent III forbade the clergy from participating in ordeals. Walking out on the procedure, the clergy effectively took God with them. And an ordeal without God was like a courtroom with no judge.

So-called investigating juries filled the judicial void. The juries were community recruits—mayors, sheriffs, and tradesmen—who lacked any notion of legal objectivity. Their investigations often amounted to nothing more than knocking on doors to gather local gossip. Suspects were allowed only to listen mutely, unable to say a single word in their own defense, as the juries recounted their hodgepodge of hearsay before a judge, so an indictment, even if it was based on rumor, was a fast track to the gallows. The fact that evidence still was not examined directly in the courtroom tipped the scales of justice heavily toward the prosecution.

Not until 1504 did English legislation call for witnesses to present their own evidence before a judge, the way they would today. An Act of Henry VII, the first to use the word “evidence,” urged anyone who witnessed the crossbow shooting of a king’s deer to testify openly at court. The Act’s promise of a ten-shilling reward blurred the line between a witness’s imagination and his memory, but the Act still led the march toward judicial examination of evidence, and a number of other acts calling for eyewitness testimony soon followed.

There were back steps, however, and a new injustice sneaked into the courtroom on the heels of the new evidence: Only the prosecution could call for testimony. Though the defendant could question witnesses rallied against him, he couldn’t call his own witnesses or speak in his own behalf. The accused, if he were allowed on the stand, the rationale went, would lie to save his skin. He would then be condemned to hell for breaking the oath of the witness. Refusing the defendant his day in court, therefore, was a supposedly compassionate means of saving his soul.

With no way to answer charges, the accused was left vulnerable to exaggeration and outright lies. As a safeguard, in serious cases like treason or murder, a judge could not consider the yammerings of a prosecution witness unless another witness confirmed them—if only one witness for the prosecution came forward, then the defendant went free. The bad news for the person in the dock was that if the prosecution could find two witnesses telling the same story, his conviction was automatic, regardless of the judge’s personal opinion.