The hunt for the perpetrators was led by Superintendent John Mallon, a Catholic who came from Armagh. Mallon had a pretty shrewd idea of who was involved. He suspected a number of former Fenian activists. A large number of suspects were arrested and kept in prison by claiming they were connected with other crimes. By playing off one suspect against another Mallon got several of them to reveal what they knew. The case was successfully prosecuted by the Attorney General, Solicitor General, James Murphy, Q.C., and Peter O’Brien, before Justice William O’Brien. Invincibles' leader James Carey, Michael Kavanagh and Joe Hanlon agreed to testify against the others. Joe Brady, Michael Fagan, Thomas Caffrey, Dan Curley and Tim Kelly were convicted of the murder, and were hanged by William Marwood in Kilmainham Gaol in Dublin between 14 May and 9 June 1883. Others, convicted as accessories to the crime, were sentenced to serve long prison terms. The getaway driver, James Fitzharris, was acquitted of murder but retried as an accessory and convicted. Only the case of Tim Kelly gave any real difficulty. He was 19 and generally said to look much younger, and by referring to him as "a child" his defence counsel created enough unease for two juries to disagree. Only after an unprecedented third trial was he found guilty.
Implications
's policy of allying his party to Gladstone's Liberal Party in 1886 to enable Home Rule was also ultimately defeated by the murders. Gladstone's Minister Lord Hartington was the elder brother of Lord Frederick Cavendish. Infuriated by the manner of his brother's early death, Hartington split with Gladstone on the Home Rule bills of 1886 and 1893 and led the breakaway Liberal Unionist Association which allied itself to Lord Salisbury's conservative governments. In the ensuing 1886 general election the Conservatives and Liberal Unionists swept the board. This delayed Home Rule by 28 years, until the Third Irish Home Rule Bill which was passed technically in 1914, but which was never effected.
Reaction
made a speech condemning the murders in 1882. This increased his already huge popularity in both Britain and Ireland. He had just enabled some reforms under the Kilmainham Treaty four days before the murders. Parnell's reputation increased in Ireland, being seen as a more moderate reformer who would never excuse such tactics. In March 1887, The Times printed letters purportedly from Parnell claiming sympathy with the murderers and that his public denunciation of them was insincere. It emerged that the letters were forgeries written by journalist Richard Pigott, and Parnell was personally vindicated by the Parnell Commission in 1888–89.
Memorial
There is a cross cut in to the grass at the location of the killings. It is long, filled with a small amount of gravel and cut thinly. In the summer of 1938 James T. Farrell visited Ireland and recalled:
