What if someone commits murder when they are younger but weren't caught till they got a mental disease like dementia?

Question

This is an episode of the fictional TV show Cold case. But I know that it can happen real life. A mother commits the murder of her husband when she's well, in her thirties or forties. The criminal investigators meet her and find that she committed the murder. However now the mother has Severe Alzheimer's/ dementia, so that she is mentally incompetent to stand trial for the murder. How would they convict her in a mental institution? Would they put her out on parole with conditions? Can they even convict her of anything since she is not mentally competent?

Answer 1

canada

Summary - the accused will not be tried if they're not fit to stand trial

The accused may be deemed unfit to stand trial, may be ordered to undergo treatment to make them fit to stand trial, and may be either detained in a hospital or released on conditions until they become fit to stand trial. They will undergo annual reviews to check whether they've become fit to stand trial and whether detention in hospital or release on conditions makes sense. The Crown must continue to show it has a prima facie case. If ever it is shown that the accused has no prospect of ever being fit to stand trial, and if they would not pose a safety risk to the public, and it is in the interests of justice, the court may order a stay of proceedings.

Fitness to stand trial

An accused is presumed fit to stand trial unless the court is satisfied on the balance of probabilities that the accused is unfit to stand trial (Criminal Code, s. 672.22)

"Unfit to stand trial" means unable on account of mental disorder to conduct a defence at any stage of the proceedings before a verdict is rendered or to instruct counsel to do so, and, in particular, unable on account of mental disorder to (a) understand the nature or object of the proceedings, (b) understand the possible consequences of the proceedings, or (c) communicate with counsel (Criminal Code, s. 2).

The court can order treatment

Upon a finding that an accused is unfit to stand trial, the court may order, for the purpose of making the accused fit to stand trial, that "that treatment of the accused be carried out for a specified period not exceeding sixty days, subject to such conditions as the court considers appropriate and, where the accused is not detained in custody, direct that the accused submit to that treatment by the person or at the hospital specified" (Criminal Code, ss. 672.58, 672.59).

The accused may be held in hospital or released on conditions, reviewed annually

Once an accused is found unfit to stand trial, the Review Board assesses the accused every year to determine whether the accused has become fit to stand trial and to review whether the accused should be in custody at a hospital or released on conditions (see generally, "The Review Board Systems in Canada: An Overview of Results from the Mentally Disordered Accused Data Collection Study").

The Crown must continue to have a prima facie case

A court will also review the Crown's case every two years to check that the Crown continues to have a prima facie case. Where the Crown fails to show a prima facie case, the court must acquit the accused (Criminal Code, s. 672.33).

The court may order a stay of proceedings

If at any point the court conducts an inquiry and determines that the accused is not likely to ever become fit to stand trial and does not pose a significant threat to the safety of the public, the court may order a stay of proceedings (Criminal Code, s. 672.851).

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^{One may wonder about limitations periods. The only requirement is that summary charges (the lighter version of charges in Canada) must be brought within 12 months of the incident. For indictable offences, there is no such time limit. Regardless, if someone has become an "accused" within the circumstances of this answer, it's only because a charge has been brought within the required time.}

Answer 2

Having “severe Alzheimer’s/dementia” does not (necessarily) make one unfit to stand trial

new-south-wales

Questions of fitness are usually raised at the committal stage where the case is before a magistrate but the can be raised at any point in the process by the prosecution, the defense, or the magistrate/judge.

If that happens, the case is stayed while a Supreme Court judge conducts a fitness hearing. These are usually quick (less than a day), and are often, but not always, conducted “on the papers”, that is, without taking oral testimony. Of course, the preparation of expert reports is usually not so quick.

A fitness hearing has three possible outcomes:

1. Fit to stand trial. The criteria here is if “the accused can understand a trial, instruct lawyers and decide on a defence, among other things. The judge will also consider whether the trial process can be modified, or assistance provided, to facilitate the accused’s understanding and effective participation in the trial.” So, in theory, a person might be unable to function in day-to-day life, yet still be fit to be tried.

2. Unfit, but likely to become fit within the next 12 months. Such as a person with mental illness who is now receiving treatment.

3. Unfit and unlikely to become fit within the next 12 months.

If the person is found to be fit, the normal criminal procedure is resumed, perhaps with modifications to accommodate the accused.

Where the accused is likely to become fit within the next year, the judge must refer them to the Mental Health Review Tribunal (MHRT) who will monitor them and advise the court when they become fit. Or, they may decide that it is not likely the accused will become fit within a year.

Where the time horizon is more than a year, the prosecutor will determine, after consultation with the victim(s) if it is the interests of justice for the prosecution to continue.

If the prosecution does continue the accused is tried in a ‘special hearing’. A ‘special hearing’ is usually a judge only trial that follows normal criminal procedure as closely as possible, however, they have different verdicts than a normal trial: not guilty; to have committed an offence, based on the limited evidence available; to have committed an offence available as an alternative to the offence charged, based on the limited evidence available; act proven but not criminally responsible.

“If the accused is found to have committed an offence (based on the limited evidence available) the judge will impose the same penalty the accused would have received if found guilty in a normal criminal trial.

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The MHRT will then assess the accused and recommend whether they should be detained in a mental health facility for treatment (which the accused has to agree to) or in prison.

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During the limiting term, the MHRT will continue to review the accused. If it finds the accused has become ‘fit’, the ODPP may decide to continue prosecuting the case as a normal criminal matter and the accused may face a normal criminal trial.

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While the ‘limiting term’ is a maximum detention period, if the MHRT finds a person who is due for release remains a risk to themselves or others, it can make them an involuntary mental health patient, or the Minister responsible for the legislation can make an application to the Supreme Court to extend the limiting term.”

“If, after a special hearing, the court finds that the act is proven but the accused is not criminally responsible a similar process applies as when a court delivers a guilty verdict in a normal criminal trial.”