Carey was son of Francis Carey, a bricklayer, who came from Celbridge, in Kildare, to Dublin, where his son was born in James Street in 1845. He also was a bricklayer, and for 18 years continued in the employment of Michael Meade, builder, Dublin. He then started business on his own account as a builder at Denzille Street, Dublin. In this venture he was successful; he became the leading spokesman of his trade and obtained several large building contracts.
During all this period Carey was engaged in a nationalist conspiracy, but to outward appearance he was one of the rising men of Dublin. Every one believed in his piety and public spirit; there was hardly a society of the popular or religious kind of which he did not become a member, and at one time he was spoken of as a possible lord mayor. In 1882 he was elected a town councilor of Dublin, not on political grounds, but, as he himself said, solely for the good of the working men of the city.
About 1861 he had joined the Irish Republican Brotherhood, and soon after became treasurer. In 1881 he broke with the IRB and formed a new group which assumed the title of the Invincibles, and established their headquarters in Dublin. Carey took an oath as one of the leaders. The object of the Invincibles was to remove all "tyrants" from the country, and several attempts, but without success, were made to assassinate Earl Cowper and W. E. Forster.
No. 1, the secret head of the association, then gave orders to kill Thomas Henry Burke, the under-secretary to the lord-lieutenant. On May 6, 1882, nine of the conspirators proceeded to the Phoenix Park, where Carey, while sitting on a jaunting-car, pointed out Burke to the others, who at once attacked and killed him with knives, and at the same time also killed Lord Frederick Cavendish, the newly appointed chief secretary, who happened to be walking with Burke.
For a long time no clue could be found to the perpetrators of the act; but on January 13, 1883, Carey was arrested and, with 16 other people, charged with a conspiracy to murder public officials. When arrested he was erecting a mortuary chapel in the South Dublin Union, and the work was then carried on by his brother Peter Carey. On February 13, Carey turned queen's evidence, betrayed the complete details of the Invincibles and of the murders in the Phœnix Park. His evidence - together with that of another informer, the getaway driver Michael Kavanagh - resulted in the execution by hanging of five of his associates.
His life being in great danger, he was secretly, with his wife and family, put on board the Kinfauns Castle, bound for the Cape, and sailed on July 6 under the name of Power. On board the same ship was Patrick O'Donnell, a bricklayer. He became friendly with Carey, without knowing who he was. After stopping off in Cape Town, he was informed by chance of the real identity of Carey. He went with his victim on board the Melrose in the voyage from Cape Town to Natal, and when the vessel was 12 miles off Cape Vaccas, on July 29, 1883, using a pistol he had in his luggage, shot Carey dead.
Carey married in 1865 Margaret m'Kenny, who, with several children, survived him.
- The Argus, Melbourne, March 13, 1883, p5, "THE PHOENIX-PARK MURDER. CONFESSION OF THE CAR-DRIVER"
- Moloney, Senan (2006). The Phoenix Murders: Conspiracy, Betrayal and Retribution. Dublin: Mercier Press. pp. 250 et passim. ISBN 1-85635-511-X.
- McCracken, J. L. (2001). The Fate of an Infamous Informer. Dublin: History Ireland.
- Moloney, Senan (2006). The Phoenix Murders: Conspiracy, Betrayal and Retribution. Dublin: Mercier Press. pp. 258 et passim. ISBN 1-85635-511-X.