PP v LIM POO TECK [2024] 2 MLRA 371

PP v LIM POO TECK [2024] 2 MLRA 371

Court Of Appeal, Putrajaya

Legal Insanity and Medical Insanity


Facts of the case


1.    The Respondent faced charges for murdering his sister, Lim Poh Ling, as specified under Section 302 of the Penal Code. The pathologist (SP6) determined the cause of death to be ‘multiple slash wounds to the head and neck.

2.    During the trial, a psychiatric specialist Dr Saramah Binti Mohd Isa from the prosecution testified that the Respondent was mentally competent to stand trial and defend himself. The Respondent had a history of schizophrenia, receiving treatment from the University Malaya Medical Centre (UMMC) until he stopped in 1998.

3.    Based on the prosecution’s evidence both oral and documentary, the trial Judge found on the balance of probability that the respondent was of unsound mind at the time of commission of the offence and did not know the nature of his act.

4.    The trial Judge, after considering both oral and documentary evidence presented by the prosecution, concluded that the Respondent was likely of unsound mind at the time of the crime, unaware of the nature of his actions. Consequently, the Judge acquitted and discharged the Respondent without requiring a defence, directing him to Hospital Bahagia Ulu Kinta, Perak for further treatment.

5.        The prosecution appealed this decision, questioning whether the Judge had the authority to order an acquittal solely based on the medical evidence presented during the prosecution’s case.



Whether the judge can order an acquittal based on the medical evidence only?



Whether the judge can order an acquittal based on the medical     evidence only?

(a)         The provided passage suggests that the authors of Ratanlal and Dhirajlal’s Law of Crimes, 26th edition, have clarified the difference between legal insanity and medical insanity. According to their explanation, the distinction is outlined on page 307 as follows:

“Medical insanity’ and ‘legal insanity’. − There is a good deal of difference between ‘medical insanity’ and ‘legal insanity ‘and courts are concerned only with the legal and not the medical aspect of the matter. It is not every kind of frantic humour or something unaccountable in a men’s action, that points him out to be a mad man, to be excepted from punishment. It is not mere eccentricity or singularity of manner that would suffice the plea of insanity. Abnormality of mind is not by itself sufficient to show that the accused must have acted while of unsound mind. Such exemption can be claimed only when the insane person is incapable of knowing the nature of the act or he is doing either wrong or contrary to law.”


(b)         In the case of PP v. Shalima Bi [2016] 5 MLRA 429, the Respondent was charged with murder for allegedly causing the death of another person by pouring hot oil on them.  During the trial, she claimed insanity, leading to her acquittal and was discharged by the trial judge, who found no prima facie case against her. Dissatisfied, the prosecution appealed to the Court of Appeal, which ordered the respondent to enter her defense. Upon presenting her defense, the trial judge again acquitted her on the grounds of insanity, directing her detention at Tampoi Hospital for treatment.

(c)          A differentiation exists between the concepts of legal insanity and medical insanity.  Not every manifestation of insanity results in the exemption of an individual from criminal responsibility. Section 84 of the Penal Code specifically deals with legal insanity and grants such exemption. The type of insanity contemplated by Section 84 pertains to the impairment of cognitive faculties. For an individual to be exempted, this impairment must be of a nature and extent that renders the offender incapable of understanding the nature of their actions or recognizing that what they are doing is wrong or contrary to the law. Consequently, the assessment of the criminality of an act is based on the criteria established in Section 84, distinct from the medical criteria.

(d)         The defence of insanity is raised in which the Court thus is required to consider two matters, namely:

(i)            whether the accused person has successfully established, as a preliminary issue, that at the time of committing the act he was of unsound mind, and

(ii)           if he was of unsound mind, whether he has proven that his unsoundness of mind was of a degree to satisfy one of the tests earlier mentioned ie, that the accused was incapable of knowing the nature of his act as being wrong or against the law. (see Ratanlal and Dhirajlal’s Law of Crimes, 5th edn, p 289 et seq).

(e)          Established legal precedent dictates that the responsibility of proving the defense of insanity lies with the individual asserting it (refer to Juraimi Hussein v. PP [1997] 2 MLRA 342 and Baharom v. PP [1960] 1 MLRA 359).  Importantly, only the accused has the right to raise the defense of insanity, and neither the Court nor the prosecution is permitted to introduce it (see PP v. Misbah bin Saat, supra).

(f)               When an accused person asserts the defense of insanity, the standard of proof required is on a balance of probabilities, akin to a civil case (as established in Rajagopal v. PP [1976] 1 MLRA 90 and Goh Yoke v. PP [1969] 1 MLRA 366). Therefore, if the appellant is able to demonstrate, based on evidence from the prosecution or other sources, that they committed the crime but were insane at the time, they cannot be held criminally responsible under Section 84 of the Penal Code.

(g)             Section 84 stated that:-

Nothing is an offence which is done by a person who, at the time of doing it, by reason of unsoundness of mind, is incapable of knowing the nature of the act, or that he is doing what is either wrong or contrary to law”.




1.            Upon determining that the prosecution had successfully established the offense of murder, it was the duty of the learned trial judge to instruct the respondent to present their defense. The failure to do so renders the final decision seriously flawed.  The Court of the view, it was premature for the judge to address the medical situation at this stage. Instead, he should have proceeded with the trial, allowing for the presentation of the defence’s version. The learned trial judge committed a significant legal error by primarily relying on the expert opinion and factual evidence related to the circumstances leading to the death, as presented by medical officer, which influenced his conclusion. This error warrants intervention by the appellate court.

2.            The orders of acquittal and discharge is set aside. The case was also to be ordered remitted to the Kuala Lumpur High Court before the same judge for continuation of the trial and the Respondent to be called to enter upon his defence. The Respondent is to be remanded in prison until trial.



Key Take Away


1.    The defense of insanity requires the accused to prove, on a balance of probabilities, that they were of unsound mind at the time of the crime and incapable of understanding the nature of their actions or recognizing that it was wrong or against the law. The court should consider both the establishment of unsoundness of mind and its degree, as outlined in legal precedent.

2.    The failure to properly consider these factors, as illustrated in the discussed cases, can lead to flawed decisions and necessitate intervention by the appellate court, resulting in a remittance of the case for further trial proceedings


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