Laurence Shirley was born on August 18, 1720, into English nobility. He was the eldest son of Laurence Ferrers, the third son of the first Earl Ferrers. From a young age, Ferrers was groomed within aristocratic circles and began his education at Oxford University. However, his academic path was abruptly cut short when, at age 20, he left university and fled to Paris, France, where he developed a reputation for living a debauched lifestyle, including indulging in gambling, alcohol, and sex.

His life took a significant turn in 1745, at age 25, when he inherited the Earldom of Ferrers and vast estates in Leicestershire, Derbyshire, and Northamptonshire, following the death of his mentally unstable uncle, the 3rd Earl Ferrers. He took up residence at Staunton Harold Hall, a large estate in northwest Leicestershire.

In 1752, Ferrers married Mary Meredith, the youngest sister of Sir William Meredith, 3rd Baronet. The union was turbulent from the start. Ferrers was described as temperamental, eccentric, and prone to violent outbursts such as traits that were said to run in the family. He openly drank, engaged in affairs, and even fathered illegitimate children. Mary, a refined woman of her time, became distressed by his behavior and filed for a legal separation in 1758.

Following the separation, the management of Ferrers’ estates was handed over to trustees, a move intended to curb his increasingly erratic control. One of the trustees' appointees was Mr. Johnson, a longtime family steward who had remained loyal to the family's interests, not the Earl’s personal agenda.

On the morning of January 18, 1760, Laurence Shirley summoned Mr. Johnson, the family steward, to Staunton Harold Hall under the guise of discussing estate business. Johnson, acting on behalf of the trustees and Mary, arrived as instructed and was directed to Ferrers’ study.

Without warning, Ferrers produced a pistol and shot Johnson in cold blood, the bullet lodging into his body. Remarkably, Johnson survived the initial shot and was offered treatment inside the house. However, instead of mercy, Ferrers who is visibly drunk and aggressive, berated the injured man while delaying medical attention. It wasn’t until Dr. Thomas Kirkland, a local physician, intervened that Johnson was transported to his home. He died the following morning, succumbing to his injuries.

The murder of a steward was a shocking scandal in 18th-century England. Ferrers was arrested and, in April 1760, stood trial before his fellow peers at Westminster Hall. The prosecution was led by Attorney General Charles Pratt, and the defense rested on a plea of insanity. Though the defense was supported by evidence of family mental illness and Ferrers’ violent behavior, the jury of peers rejected it.

Despite Ferrers' eloquence and self-representation in court, his fate was sealed. Interestingly, Ferrers later admitted that his insanity plea was not genuine. He said he had entered it only to satisfy his family and was embarrassed by it, remarking that even religious figures like Lady Huntingdon and preacher George Whitefield could not “convert” him.

On May 5, 1760, at age 39, Lord Ferrers was executed at Tyburn, becoming the last British peer ever hanged. He was escorted from the Tower of London in his own carriage, dressed in a light-colored embroidered suit, the same one he had worn on his wedding day. Some reports say, as a final concession to his aristocratic rank, he was hanged using a silk rope.

Following his death, his body was dissected at Barber-Surgeons' Hall, Monkwell Street, London