Thomas Jeffrey was born around 1791 in Bristol, England, into the household of a butcher. After seven years of schooling, he embarked on a naval career, first serving on the warship Achille, but deserted after over four years citing abuse. He then became a drummer in the Army, only to desert again, revealing early patterns of insubordination. Jeffrey returned to maritime life aboard the Leander, but ultimately drifted into a life of petty theft and violent crime.

In the years following 1814, his behavior escalated. He robbed relatives, including his father, uncle, and a family acquaintance, then joined an armed group that robbed farmers in England. One such robbery resulted in the shooting death of a farmer who resisted — although Jeffrey was released after six months in jail due to lack of evidence. Following his release, he continued committing burglaries in the East Midlands and was finally arrested in Leicester in 1817. On 29 July 1817, he was convicted at the Nottingham Assizes and sentenced to transportation for life.

Jeffrey was placed aboard the prison hulk Retribution at Woolwich, and in 1819, was transported to New South Wales aboard the Prince Regent. Upon arrival in Sydney in January 1820, he initially worked for a settler on the Hawkesbury River, later assigned to a boat crew. But within months, he was convicted of stealing oranges and sentenced to 100 lashes and two years in the Newcastle coalmines. He escaped from a work-gang with six others, and during their trek back to Sydney, two of the men were murdered and cannibalized — a brutal foreshadowing of crimes to come. Jeffrey was eventually recaptured and reassigned multiple times.

Persistent in his defiance, Jeffrey escaped again, roamed the Emu Plains, joined a band of convicts in Cowpastures, and was betrayed and jailed once more. Offering information to the magistrate John Macarthur, he was not pardoned but was transferred to the harsh penal colony of Van Diemen’s Land (Tasmania) in January 1822.

Jeffrey's behavior remained erratic and violent. Though originally slated for the notorious Macquarie Harbour penal station, he instead remained in George Town. In 1824, he threatened to stab a chief constable and received 12 months’ punishment, though not at Macquarie Harbour. By 1825, he had become the flagellator and watch-house keeper at Launceston Gaol, feared for his cruelty. Eyewitness accounts describe prisoners lacerated from throat to belly for minor infractions. Reports suggest women were also abused, confined unjustly, and subjected to sexual assault — including an incident involving a free woman, Mrs. Elizabeth Jessop. Despite repeated disciplinary infractions, including drunkenness and false imprisonment, Jeffrey remained in his post — possibly protected by the magistrate, Peter Mulgrave.

Jeffrey later blamed his descent into violence on being assigned as watch-house keeper, claiming that the access to alcohol and unchecked authority “was the total ruin of me.” By late 1825, with enemies building and punishment looming, he made a final escape — this time with murder in mind.

In mid‑December 1825, Thomas Jeffrey and his three convict accomplices—John Perry, Edward Russell, and James Hopkins—arrived at James Sutherland’s “Rothbury” grazing run, nestled between Cressy and Campbell Town on the Isis River. They lingered there for nearly ten days, feasting on slaughtered stock and relaxing as if the land were theirs. But on Christmas Day, things turned violent. The four looted an unattended tent hut and helped themselves to a bottle of rum. As they departed, a shot rang out—startling them but going nowhere. At a cautious approach, they encountered two men with muskets. Upon identifying himself, Jeffrey exchanged shots with one, grazing the man’s thigh. When they drew closer, the wounded but inebriated man began hurling abuse. Seizing the moment, Russell crept behind and delivered a fatal shot to the head. The victim, simply identified in newspapers as “Mr. Sutherland’s man,” was left behind, dead in the bush. 

From that point, urgency consumed the fugitives. They woke a sleeping man inside a hut 800 yards from Sutherland’s home. He offered to show them where to cross the Isis River safely. Crossing, they raided “Young’s residence,” home to “Old McShann.” The elderly occupant and a companion were coerced into carrying the stolen goods into the bush; they were then released unharmed. 

The violence escalated dramatically on the morning of 31 December 1825, when Jeffrey, Perry, and Russell ambushed two men splitting wood near settler George Barnard’s hut (in modern-day Rocherlea). They bound one man, Samuel Russell (not to be confused with Edward), who summoned his employer, John Tibbs, and his family. Jeffrey’s group forced Tibbs, his wife Elizabeth, their five-month-old son, and one of Barnard’s laborers into the bush. As they moved, Russell shot and killed Isaac Beechy, a neighboring stockkeeper, while Perry shot Tibbs in the neck. Although wounded, Tibbs escaped and raised the alarm in Launceston. Beechy succumbed to his wound on 9 January 1826. Jeffrey callously shrugged, saying Beechy “would not have been shot at” had he been more agreeable.

On New Year’s Eve, 31 December, they kidnapped John and Elizabeth Tibbs and their infant. Isaac Beechy, a stock-keeper, was fatally shot; Tibbs was wounded but escaped to raise the alarm. In a chilling act, Jeffrey or Russell killed the infant by bashing its head against a tree when the family couldn't keep pace. Jeffrey mockingly told the distraught mother they had “sent it to Mr. Barnard’s”.

The group trudged on with their captives. At some point, Jeffrey seized the child from his terrified mother—apparently because she was slowing the group’s pace. Elizabeth Tibbs begged, “the villain is gone to murder my child.” Jeffrey returned without the baby fifteen minutes later, falsely claiming he’d sent him back to Barnard’s. In reality, either Jeffrey or Russell had smashed the infant’s head against a tree, killing him instantly. William Tibbs later said Jeffrey told the distraught mother that her child “smiled upon him in the bloody act.” When the child’s body was found on 7 January, parts had been eaten by animals.

That night, haunting cruelty followed. Jeffrey made tea for Mrs. Tibbs and Samuel Russell and forced Mrs. Tibbs to sleep next to him on a makeshift bed of blanket and kangaroo rug about six yards from a fire. Nothing was said, but he could hear her crying. At dawn, he released Mrs. Tibbs and guided her down a hillside toward safety.

As the fugitives pressed on, they nabbed William Bruce, a mailman, along the Tamar River. On 11 January, Bruce fetched a stranger who turned out to be Constable Magnus Bakie, part of a search party. Jeffrey, accusing the constable of treachery, executed him promptly: “I put my pistol to [Bakie’s] head and immediately shot him,” he later confessed.

After several days, Jeffrey shot a cockatoo, their only meal. Desperate, Perry declared, “the first man that falls asleep shall be shot, and become food for the other two.” Predictably, Edward Russell was the one who succumbed to fatigue; Perry shot him in the forehead and then butchered his flesh. They broiled it, mixing it with mutton stolen from a shepherd’s hut they raided on 19 January. Russell’s flesh was cooked into steaks and eaten.

Jeffrey was captured near Evandale on 22 January 1826 after an Aboriginal tracker recognized him. The mob nearly lynched him on sight. In April 22, Jeffrey stood trial in Hobart—convicted for the infant’s murder, Bakie’s murder, and robbery. On May 4, 1826, he was executed by hanging in front of Hobart Gaol.