The long-awaited Bill reforming the law on criminal insanity is expected to be brought to the Cabinet today.
It will update the definition of mental disorder and re-state the law on fitness to plead. A new verdict, "not guilty by reason of insanity", will be introduced, replacing the existing verdict of guilty but insane.
It will also contain a new provision, where a person can be found guilty but with diminished responsibility, allowing a verdict of manslaughter to be brought in where normally the crime would be murder but the suspect is not in full possession of his mental faculties.
The Bill will also provide for a new, independent body to consider the ongoing detention of people found not guilty by reason of insanity. The Mental Health Review Board will be obliged to keep the detention of such people under review and decide on whether and when they can be released.
At the moment this is decided by the Government, following the old British law, where a person was detained "at Her Majesty's pleasure". Throughout the 1970s and 1980s it was tossed between the Government and the courts, until this was finally decided by the Supreme Court, which stated that the responsibility for releasing such detainees lay with the Government.
According to the European Convention on Human Rights, decisions on detention must be made by bodies with judicial powers, and the Mental Health Review Board will have such powers. The Bill will also contain other human rights guarantees.
It will bring modern knowledge into the law on criminal insanity for the first time, with a detailed definition of mental illness. This will not include personality disorders, as claimed by John Gallagher, who murdered Anne Gillespie and her mother in 1988. Within months he claimed he had regained his sanity and began a campaign for his release.
It will also contain a major restatement of the law on fitness to plead. The question of fitness to plead will not be decided in the District Court, but will go to the Circuit Criminal Court for consideration.
The prosecution will have the right to appeal a verdict of not guilty by reason of insanity, or guilty with diminished responsibility. Some of the provisions of the new Bill were drafted over 20 years ago, in a Bill based on a report drawn up by a committee chaired by Mr Justice Seamus Henchy.
However, it has languished in the legislative doldrums since, with successive Ministers for Justice promising to tackle it as a matter of urgency.
It is understood Mr McDowell is anxious to update this outdated legislation once and for all, and has been eager to bring the Bill to Cabinet before Christmas. There may still be anomalies between it and the Mental Health Act recently introduced by the Minister for Health and passed by the Oireachtas, but Mr McDowell is understood to be confident these can be ironed out at Committee Stage.