The court tries offences under the following laws: Conspiracy and Protection of Property Act 1875 Explosive Substances Act 1883 Offences against the State Act 1939 Firearms Act 1925 to 1990 Criminal Damage Act 1991Offences under these acts are known as "scheduled offences". These scheduled offences range from illegal possession of , to importing seditious foreign newspapers, to threatening to damage property. The court can also try other, non-scheduled offences if the Director of Public Prosecutions issues a certificate stating that the ordinary courts are inadequate to handle the case.
Although the court was initially set up to handle terrorism-related crime, it has been handling more and more organized crime cases after the Provisional IRA ceasefire in the 1990s. For instance, members of the drugs gang which murdered journalist Veronica Guerin were tried in the Special Criminal Court.
Most famous is the case of Nicky Kelly, who was convicted along with two other men by the Special Criminal Court in 1978 of carrying out the Sallins Train Robbery. All three convictions were later overturned after it was found that the suspects had been assaulted by gardaà while in custody.
In 2003, Michael McKevitt was convicted of "directing terrorism" and "membership of an illegal organization" for his role as leader of the Real IRA. In 2001, Dundalk man Colm Murphy was convicted of "conspiracy to cause an explosion likely to endanger life or cause injury", in connection with the Omagh bombing . In January 2005, Murphy's conviction was quashed and a retrial ordered by the Court of Criminal Appeal, on the grounds that two gardaà had falsified interview notes, and that Murphy's previous convictions were improperly taken into account by the trial judges. Relatives disappointed with Omagh ruling — ''RTÉ News article, 21 January 2005