It was just after four in the afternoon on the 11th of June 1906, when the quiet of a leafy suburban road in Camberley, Surrey, was shattered. Neighbors of fifty-three-year-old Caroline Hog saw her stagger from the grounds of her home, Heathfield, clutching her throat and crying out that she was murdered. She made it to the house next door, where Mrs. Wilding came to her aid.

Caroline was bleeding and distressed, but she managed to utter two words: “My sister, my sister. ” Doctors were summoned, and a neighbor, Colonel Lonsdale Augustus Hail, hurried to Heathfield to warn the other sister, Mary Anne Hog, of what had happened. He found the front door slightly ajar and went in. Mary Anne lay on the hall floor, a wound to her head and a deep gash across her throat.

She was dead. A police constable arrived as the colonel called for help, and the men searched the house. The drawing room was undisturbed, the dining room laid out for a meal for one, and the garden door closed. There were no signs of an intruder.

But in the dead woman’s hand lay a four-inch claw hammer, which fell to the floor the moment she was touched. Its shaft was broken, lying five feet away, and nearby was a heavily bloodstained piece of merino cloth. The police believed the cloth had been wrapped around the hammer to muffle the blows. No knife or sharp implement that could account for the two women’s cut throats was found.

Caroline’s own wounds were dressed, and she was taken to a nursing home. She was not considered to be in danger. The two sisters were half-sisters, born sixteen years apart. Mary Anne Hog, sixty-eight, was the elder, the daughter of a physician and the second of eight children.

When her mother died, her father remarried and had Caroline in 1853. Neither woman had ever married, and circumstances had thrown them into a domestic arrangement at Heathfield House, a large property with grounds, stables, and no live-in staff. They had lived abroad for years, spending much of their time in Yokohama, where they were known as a pair of eccentric European ladies who dressed shabbily. They returned to England in 1903 and settled back in Camberley.

The local view was that Caroline had money and Mary depended on her. Caroline confirmed this herself, telling the inquest that her sister relied entirely on her generosity. It was not true. Mary had a healthy fortune of her own, one that exceeded her younger sister’s.

Inspector Frederick Fox of Scotland Yard was called in to lead the inquiry. He found the house generally untidy, but no signs of a ransacking. Drawers in the dining room stood open, yet valuables, silverware, plate, and even a gold sovereign in an Indian bowl had been left untouched. A blood trail led to the basement scullery, where there were blood splashes on the walls and floor.

A basin of water on a table had clearly been used to wash bloodied hands, and a damp towel had been used to dry them. No other exit was apparent, and no blood was found outside. The first doctor to examine Mary’s body placed the time of death at about 4:15 p. m.

, and a local housekeeper reported seeing Mary looking out of an upper window just before 3:25 that afternoon. Caroline’s account of events shifted repeatedly. She said her sister had entered her bedroom between two and three, telling her she had canceled the carriage Caroline had hired for that afternoon because the weather looked threatening. Mary left and went downstairs.

Caroline then said she had risen and heard a cry, gone out onto the landing, and met a man at the top of the stairs, a stranger with a net over his head who demanded money. She told him the money was downstairs. They rushed down together, though she could not say who went first. She claimed she saw her sister in the front garden, blood streaming from her face, and was struck from behind as she went toward her.

The man, she said, had a pickaxe or hammer with a long handle, which he swung with both hands. She did not know when her throat was cut, only that she managed to escape to the road for help. She never saw her sister again. Her descriptions of the attacker varied and grew more detailed under questioning: a man of about thirty-five, five feet eight, with dark eyes, a red complexion, and his sleeves rolled up, resembling a respectable working man like a bricklayer.

The police circulated this description and searched for the man. They visited Broadmoor Asylum, just four miles away, but found no escapees. Odd sightings in the area came to nothing. One man confessed to the murder but clearly knew nothing of it.

Police dug up parts of the garden searching for a knife and found nothing. Then Inspector Fox discovered a black-handled kitchen knife in the scullery, with faint traces of blood, recently washed and dried. He concluded it was the murder weapon, cleaned and returned to its place, and that the hammer had been deliberately placed in the victim’s hand. The killer, he believed, had gone to great lengths to conceal the crime.

The Home Office pathologist, Professor Augustus Pepper, conducted the post-mortem. He determined that Mary had been felled from behind by several powerful blows from the wrapped hammer, which had rendered her unconscious without fracturing her skull. Her throat had then been cut deeply, the wound made from left to right by a right-handed person while she lay helpless. He noted that Mary’s injuries and Caroline’s injuries showed great similarity and exhibited all the appearances of murder and attempted murder.

Asked directly whether one woman could have inflicted all the injuries, he said yes. Asked about Caroline’s testimony, he was blunt: as a medical man, he did not consider her statement reliable at all. The inquest reconvened on the 10th of July. The first witness was a builder’s laborer who identified the hammer as his own.

He had been working near Heathfield House that day, and he and his brother had seen the hammer at six o’clock that morning. They had not noticed it missing until police showed it to them days later. Caroline then gave her evidence before the coroner, dressed in black mourning, pale and speaking in a faint voice. The coroner pressed her relentlessly, pointing out that she had made many different statements.

She contradicted herself on where she met the man, on who rushed down the stairs first, on whether she went into the garden, and on how she had escaped. At one point she claimed all three of them, herself, her sister, and the man, had gone into the garden. At another, she said she had gone toward the dining room door, though why she would do that when trying to escape was unclear. She insisted she had not been in the scullery, and she introduced, for the first time, the claim that a purse with seventeen or eighteen shillings and a George III prayer book were missing.

The press reported the testimony under the banner: Sister’s graphic but contradictory evidence. The jury retired and returned a verdict of willful murder against person or persons unknown, stating there was insufficient evidence to show by whom it was committed. The case was never solved. The inquest was the end of the matter.

But the evidence available to the authorities, and the circumstances of the two women’s lives, pointed in a direction the official verdict did not go. Mary was not the poor dependent her sister claimed. Her probate was later valued at £5,293, the equivalent of more than £800,000 today, and was left entirely to Caroline. Far from being impoverished, Mary had been quietly wealthy, and she had allowed her sister to believe otherwise, ensuring Caroline paid the household bills while Mary did the work.

It was Mary who rose early, who bought the food, who did the housework, and who brought her sister breakfast in bed, often as late as two in the afternoon. Caroline expected dinner to be waiting when she rose, and said so at the inquest. The two women squabbled constantly, over shopping, over money, over the unlocked front door that Mary insisted on leaving open when she went out, a habit that infuriated Caroline, who told the servant she would one day be murdered in her bed. On the morning of the attack, the hammer had been taken from a builder’s barrow near the house.

Only Mary habitually went out in the morning. She had wrapped it in cloth, and a former charwoman recalled that Mary had a habit of wrapping a hammer in cloth to break coal quietly so as not to wake her sister. But it was June, and no fires were being lit. The cloth served another purpose, muffling both sound and blood.

The fight appears to have begun in the basement scullery, where blood was splashed on the walls and the basin held bloody water. Mary was struck about the head, ran bleeding up the stairs toward the front door, and was cut down from behind. Her throat was cut while she lay unconscious. The kitchen knife was cleaned, dried, and returned to its drawer.

The hammer was placed in the dead woman’s hand, a crude attempt to suggest self-defense or a struggle. The dining room drawers were pulled open, but nothing was taken. An intruder who had come to rob would have taken the silver, the sovereign, the purse. An intruder would not have washed his hands in the basement before fleeing as his victim ran into the street screaming for help.

The police and the coroner had their suspicions, and the jury’s verdict left the matter unresolved, but the evidence pointed to only one person who had reason to kill Mary Hog, who stood to gain her money, and who had the time and presence of mind to stage the scene. Caroline Hog left Camberley after her sister’s death and returned to Yokohama, where she lived at the Grand Hotel. She made her will in 1915, leaving her wealth to a Norwegian businessman with whom she had significant investments.

She died in Yokohama on the 18th of September 1921, at sixty-eight, the same age her sister had been when she was murdered in the hallway of Heathfield House fifteen years earlier.