Michael Manning was born on 1 September 1928 in Limerick, Ireland, into a modest working-class family. He lived a relatively quiet life and had been employed as a laborer. Little is documented about his early life, but reports describe him as a man of average background, with no significant criminal history before the murder that would ultimately define his life and end it.

At the time of the crime, Manning was 25 years old and working in Limerick. He was not married and lived a relatively low-profile existence.

On the evening of 18 November 1953, Michael Manning committed the murder that would mark the final chapter of his life and earn him a dark place in Irish legal history.

His victim was Catherine Cooper, a 65-year-old nurse at Barrington's Hospital in Limerick. According to trial records, Manning had been drinking heavily that evening and encountered Cooper on her way home. In what was described as an alcohol-fueled attack, Manning sexually assaulted and strangled her near the hospital grounds. Her body was later discovered in the hospital vicinity, triggering a police investigation that quickly led to Manning.

He was arrested within days and confessed to the crime, expressing regret and sorrow. During his trial, which began in early 1954, Manning pleaded guilty to murder. Despite his remorse, the nature of the crime and the evidence against him left the court with no choice under Irish law at the time. On 25 February 1954, Manning was convicted of murder and sentenced to death by hanging.

His execution took place at Mountjoy Prison in Dublin on the morning of 20 April 1954. The executioner was Albert Pierrepoint, a well-known British hangman. Manning had received spiritual counsel prior to his death and reportedly accepted his fate with calm resignation.

Michael Manning became the last person to be executed in the Republic of Ireland. His death sparked increased public debate about capital punishment, and in 1964, just a decade later, the Irish government abolished the death penalty for most crimes. By 1990, the death penalty was fully abolished under Irish law.

Manning’s final words were reportedly filled with remorse:
“I am sorry. I wish to God I hadn't done it.”