The right to trial by jury was suspended for certain "scheduled offences" and the court consisted of a single judge. The courts were revised by the Justice and Security (Northern Ireland) Act 2007, but remain in use in much the same format. The trial of Brian Shrivers and Colin Duffy for the murder of two British soldiers during a Real IRA gun attack on Massereene army base in Antrim town in 2009, was heard in a Diplock court in January 2012.
The courts were established in response to a report submitted to Parliament in December 1972 by Lord Diplock, which addressed the problem of dealing with Irish republicanism through means other than internment.
Lord Gardiner's Minority Report as part of the Parker Report in March 1972 found "no evidence of [intimidation] or of perversity in juries". The report marked the beginning of the policy of "criminalisation", whereby the State removed legal distinctions between political violence and normal crime, with political prisoners treated as common criminals. The report provided the basis for the Northern Ireland (Emergency Provisions) Act 1973, which, although later amended (with the Prevention of Terrorism (Temporary Provisions) Act 1974 and subsequent renewals), continued as the basis for counter-terrorist legislation in the UK.
Until recently the Diplock courts only tried Republican or Loyalist paramilitaries. In the first case in which a person not associated with the Troubles was tried and convicted, Abbas Boutrab, a suspected al-Qaeda sympathiser, was found guilty of having information that could assist bombing an airliner. A sentence of six years was handed down on 20 December 2005.
Diplock courts were common in Northern Ireland for crimes connected to terrorism. The number of cases heard in Diplock courts reached a peak of 329 yearly in the mid-1980s. With the Northern Ireland peace process that figure fell to 60 a year in the mid-2000s. On 1 August 2005, the Northern Ireland Office announced that the Diplock courts were to be phased out, and in August 2006 they announced that the courts were to be abolished effective July 2007. This was achieved under the Justice and Security (Northern Ireland) Act 2007.
The establishment of the Diplock Courts can be seen as an early, and successful, example of the Provisional Irish Republican Army's (PIRA's) long-term aim of making "the Six Counties... ungovernable except by colonial military rule". This was a central pillar of the "Long War" strategy set out in the 1977 Green Book: "while PIRA claimed its armed struggle sought to end British 'colonial' rule, its leadership realised that Catholic perception of British 'colonialism', and the subsequent disillusionment caused by this, was of great value in persuading the Catholic community to embrace the Republican cause."
In his report, Diplock cited two primary reasons for his determination that jury trials should be suspended
- danger of perverse acquittals, and,
- jurors had been threatened, "of which we have had ample evidence".
Two years later, Lord Gardiner's review of the removal of trial by jury included attempts to bolster Diplock's findings as follows:
We are convinced on the evidence that we have received, that if juries were to be reintroduced for scheduled offences, their verdicts would still be subject to the influences of intimidation, or the fear of it. We have no evidence of this or of perversity in juries...
The Gardiner Report found that "no evidence" existed on which the removal of the jury was based but concluded that non-jury trials should continue.
List of famous cases tried in Diplock courts
- Shankill Butchers
- Shankill Road bomber Sean Kelly
- The Christy Walsh Case
- The Milltown Cemetery attack
- The corporals killings
- Danny Morrison (writer)
- R v McCormick (1978) NI: Justice McGonigal ruled that slaps of the hand were permissible and not a form of torture or "degrading and inhumane treatment".
- Special Criminal Court: Republic of Ireland's equivalent of the Diplock courts
- Court of Castle Chamber
- Walker, Clive (2011). Terrorism and the Law. Oxford University Press. Chapter 11. ISBN 978-0-19-956117-9.
- McDonald, Henry (20 January 2012). "Brian Shivers found guilty of Massereene murders". The Guardian.
- Report of the Commission to Consider Legal Procedures to deal with Terrorist Activities in Northern Ireland (Cmmd. 5185); full text of the Diplock Report
- Greer & White: Abolishing The Diplock Courts, page 91: Report of a Committee to consider, in the context of civil liberties and human rights, measures to deal with terrorism in Northern Ireland, Lord Gardener.
- Donohue, Laura (2007): Counter Terrorist Law and Emergency Powers in the United Kingdom 1922–2000, S. 155
- "Al-Qaeda terror suspect convicted", BBC News Online, 24 November 2005
- "Al-Qaeda terror suspect is jailed", BBC News Online, 20 December 2005
- "Two jailed for life for killing policeman Stephen Carroll". ITV News. 30 March 2012.
They were tried in a 'diplock court' by a judge with no jury; common in Northern Ireland for crimes connected to terrorism.
- "Replacement Arrangements for the Diplock Court System" (PDF). (494 KiB), Northern Ireland Office consultation paper, August 2006
- "Jury trials 'to become the norm'", BBC News Online, 11 August 2006
- The Long War: The IRA and Sinn Féin, Brendan O'Brien, Syracuse University Press, page 23.
- Report of the Commission to consider legal procedures to deal with terrorist activities in Northern Ireland, Lord Diplock, H.M.S.O., 1972, page 17
- Greer & White: Abolishing the Diplock Courts, page 91.
- British plan to abolish Diplock courts next year, The Irish Times, 11 August 2006
- "Christy Walsh: a miscarriage of justice", British Irish Rights Watch website (birw.org).
- In response to the serialisation of loyalist killer Michael Stone's book. – Relatives for Justice
- Patrick Kane, Sean Kelly and Michael Timmons, Hansard, HC Deb 15 March 1995 vol 256 cc874-82
- Taylor, Peter (1999). Loyalists: War and Peace in Northern Ireland. TV Books, p. 158. ISBN 1-57500-047-4.