Criminal insanity and mental health

Information

People who are charged with a criminal offence and who are suffering from a mental disorder are dealt with under the Criminal Law (Insanity) Act 2006 as amended by the Criminal Law (Insanity) Act 2010.

The question of the mental state of someone charged with a crime may arise at 2 different stages - at the start of the trial and at the decision on guilt. If a person is suffering from a mental disorder, they may be considered unfit to be tried at the start of the trial. In that case, no trial goes ahead. If a trial is held and the person is considered to have actually committed the offence but was insane at the time, it is possible for a verdict of not guilty by reason of insanity to be reached. In murder cases, the concept of diminished responsibility may be used to substitute a verdict of manslaughter.

A mental disorder is defined in the 2006 Act as including mental illness, mental disability, dementia or any disease of the mind but does not include intoxication (drunkenness).

Fit or unfit to be tried

The decision on whether or not a person is fit to be tried is made by a judge. If the person cannot understand the charge or is unable to instruct a legal team, challenge jurors or follow the evidence, then they may be considered unfit to be tried.

This finding (that is that someone is considered unfit to be tried) is not a decision on the alleged criminal activity. If someone is found to be unfit to be tried, then the trial is postponed. The judge then decides what happens next. For example, the person may be committed to a psychiatric hospital or unit if they are considered to be suffering from a mental disorder and are in need of in-patient treatment under the terms of the Mental Health Act, 2001. Alternatively, the person may be sent for out-patient psychiatric care. The person may be committed to a psychiatric hospital or unit for 14 days in order to establish whether or not they should be sent for treatment. The person may appeal against a committal order.

If the judge considers that a person is unfit to be tried and that there is a reasonable doubt that the person committed the alleged crime, the person may be acquitted. The Director of Public Prosecutions or the accused person may appeal against a decision that they are unfit to be tried.

Not guilty by reason of insanity

A person will be considered legally insane if they were suffering from a mental disorder at the time of the offence and, as a result,

  • Did not understand what he or she was doing or
  • Did not know what he or she was doing was wrong or
  • Was unable to not commit the crime

If someone is considered to have actually committed the offence but was insane at the time, the verdict may be not guilty by reason of insanity. This decision is made by a jury where the case is tried by a jury. Where there is no jury, the decision is made by a judge. If this verdict is reached, the judge may order that the person be committed to a psychiatric hospital or unit in broadly the same way as applies in the case of being unfit to be tried.

Diminished responsibility in murder cases

If someone is charged with murder, the verdict of not guilty by reason of insanity is one possible verdict. The Criminal Law (Insanity) Act 2006 provides for the concept of diminished responsibility in murder cases. The verdict is available where someone does not meet the test for a verdict of not guilty by reason of insanity but still was suffering from a mental disorder which substantially diminished his or her responsibility for the killing.

A conviction for murder brings an automatic life sentence. In other crimes, the judge has discretion in relation to sentencing and so can take into account any diminished responsibility which may exist. If someone charged with murder successfully pleads diminished responsibility, then the verdict is manslaughter. The judge can then sentence the person to any appropriate length of time in prison.

Mental Health Review Board

The Mental Health (Criminal Law) Review Board's main function is to review the detention of those found not guilty by reason of insanity or unfit to be tried, who have been detained in a designated centre by order of a court. At present, the only designated centre is the Central Mental Hospital. The Review Board also has responsibility for people who have been convicted of offences and who become mentally ill while serving their sentences. The Review Board must have regard to the welfare and safety of the person whose detention it reviews and to the public interest. It may assign a legal representative to the person unless the person proposes to engage one.

The Board is composed of a legally qualified chairperson and a number of other people, at least one of whom must be a consultant psychiatrist. It is obliged to review each detention at least once every 6 months.

Page edited: 8 October 2020