Hugh Leonard Thompson Murphy was born on March 2, 1952, in Belfast, Northern Ireland. He was the youngest of three sons in the Murphy family, which included his two older brothers, William Jr. and John. His father, William Murphy Sr., worked as a dock laborer. The family lived in a loyalist area known as Shankill Road. They moved several times during Hugh's early life and returned to his mother's family home in lower Shankill in 1957.

As a child, Murphy did not use his first name, "Hugh," because it was similar to the common Irish Catholic surname "Hughes." This might have led to unwanted associations, considering his own surname, Murphy, was distinctive and recognizable in the area. Murphy attended Argyle Primary School, where he gained a reputation for using a knife and having his brothers back him up in conflicts. He had his first conviction at age twelve for theft.

At sixteen, he left Belfast Boys' Model School and joined the Ulster Volunteer Force (UVF), a loyalist paramilitary group. During this time, he became involved in significant rioting in Belfast in August 1969. Murphy’s views were marked by a hatred for Catholics, which he openly expressed in his conversations. He often referred to them in derogatory terms.

Despite his growing criminal behavior, Murphy held a steady job as a shop assistant. His lifestyle included heavy drinking and socializing with many young women. He committed his first known offenses in his early twenties. Physically, Murphy was of below-average height with a slim build and sallow complexion. He had blue eyes and curly dark brown hair. He was known to wear flashy clothing, often featuring leather jackets and driving gloves. He had several tattoos that displayed Ulster loyalist symbols.

Hugh Leonard Thompson Murphy, known as Lenny Murphy, was involved in various violent crimes during the Troubles in Northern Ireland. In 1972, he participated in the torture and murder of four Catholic men. On September 28, 1972, a Protestant man named William Edward Pavis was killed in East Belfast after being threatened by loyalists. Murphy and an accomplice, Mervyn Connor, were arrested for this murder. During a police line-up, Murphy disrupted the procedure but was identified by two witnesses.

Connor died in prison from cyanide poisoning before their trial. He left a note confessing to the crime and claiming Murphy was innocent. However, despite witness testimony, Murphy was acquitted in June 1973 due to concerns over the evidence's reliability. He was later re-arrested for attempting to escape from prison.

By May 1975, Murphy was released from prison and returned to Belfast. He formed a gang known as the Shankill Butchers, which included more than twenty men. In October 1975, the gang shot four Catholics during a robbery at a warehouse. Over the following months, they began abducting, torturing, and murdering random Catholic men, often dragging them off the streets at night. Murphy preferred to kill with a knife, often slashing his victims' throats.

On January 10, 1976, Murphy shot and killed a Catholic man named Edward McQuaid in a close-range attack. Murphy was eventually arrested again for attempted murder after shooting a young Catholic woman on March 11, 1976. He negotiated a plea deal and was sentenced to twelve years in prison for a firearms offense.

While he was incarcerated, the Shankill Butchers continued their killings under the command of his lieutenant, William Moore. In May 1977, many gang members, including Murphy, were arrested for their crimes. Despite confessions from other gang members naming him as the leader, Murphy denied his involvement.

After his release from prison in July 1982, Murphy resumed his violent activities, killing at least four more people in four months. He was involved in several brutal incidents, including the murder of a partially disabled man and a car seller who demanded full payment. He also kidnapped and tortured a Catholic man in his home.

On November 16, 1982, Murphy was shot dead by two members of the Provisional IRA outside his girlfriend's house. He was hit with more than twenty rounds and died instantly. Reports indicated that rival loyalists had provided information to the IRA about Murphy's movements, allowing them to track him. Following his death, he received a large paramilitary funeral with UVF honors. His tombstone read, "Here Lies a Soldier," reflecting his status in the loyalist community.