PP v Wang Zhijian: Diminished Responsibility, Murder, and Adjustment Disorder

In Public Prosecutor v Wang Zhijian, the High Court of Singapore heard the case against Wang Zhijian, a Chinese national, who was charged with multiple counts of murder and attempted murder. The court, presided over by Chan Seng Onn J, found Wang guilty of culpable homicide not amounting to murder for the deaths of Zhang Meng and Feng Jianyu due to diminished responsibility. However, he was found guilty of murder for the death of Yang Jie. The defense of diminished responsibility was central to the case, with psychiatric experts disagreeing on the extent to which Wang's adjustment disorder impaired his mental responsibility.

1. Case Overview

1.1 Court

High Court

1.2 Outcome

Accused found guilty of murder for one charge and culpable homicide for two charges due to diminished responsibility.

1.3 Case Type

Criminal

1.4 Judgment Type

Grounds of Decision

1.5 Jurisdiction

Singapore

1.6 Description

Wang Zhijian was charged with murder. The court found him guilty of culpable homicide for two charges due to diminished responsibility but guilty of murder for the third.

1.7 Decision Date

2. Parties and Outcomes

Party NameRoleTypeOutcomeOutcome TypeCounsels
Public ProsecutorProsecutionGovernment AgencyPartialPartial
Hay Hung Chun of Attorney-General’s Chambers
Charlene Tay Chia of Attorney-General’s Chambers
Mohamed Faizal of Attorney-General’s Chambers
Eunice Chong of Attorney-General’s Chambers
Wang ZhijianDefendantIndividualPartialPartial

3. Judges

Judge NameTitleDelivered Judgment
Chan Seng OnnJudgeYes

4. Counsels

Counsel NameOrganization
Hay Hung ChunAttorney-General’s Chambers
Charlene Tay ChiaAttorney-General’s Chambers
Mohamed FaizalAttorney-General’s Chambers
Eunice ChongAttorney-General’s Chambers
Jason Peter DendroffJP Dendroff & Co
Kelvin Lim Phuan FooKelvin Lim & Partners

4. Facts

  1. Wang was in a romantic relationship with Zhang, which was disapproved of by Zhang's family.
  2. Zhang's family harassed Wang, causing him to lose his job and deplete his retirement funds.
  3. Wang was subjected to bizarre treatment by Zhang during his visits to Singapore, including being confined naked in a bedroom.
  4. Wang stabbed Zhang multiple times in her abdomen area after an argument.
  5. Feng entered the room while Wang was stabbing Zhang and was also stabbed by Wang.
  6. Yang and Li were tenants in the same flat as Zhang and Feng.
  7. Wang attacked Yang and Li in their bedroom after stabbing Zhang and Feng.
  8. Yang fell to her death after Wang cut her fingers while she was holding onto laundry pole holders outside the kitchen window.

5. Formal Citations

  1. Public Prosecutor v Wang Zhijian, Criminal Case No 3 of 2011, [2012] SGHC 238

6. Timeline

DateEvent
Wang and Zhang began a romantic relationship in China.
Zhang's daughter, Feng, came to Singapore to study.
Feng secured a place in a secondary school in Singapore.
Wang's third visit to Singapore.
Zhang's death.
Feng's death.
Yang's death.
Wang gave a Cautioned Statement.
Wang gave a Long Statement.
Wang gave a Long Statement.
Wang gave a Long Statement.
Dr Koh examined Wang.
Dr Koh examined Wang.
Dr Koh examined Wang.
Dr Koh's report date.
Dr Tan examined Wang.
Dr Tan's report date.
MacArthur Violence Risk Assessment Study accessed.
Dr Koh provided further opinion.
Certified Transcript.
Judgment reserved.
The Prosecution's appeal to this decision in Criminal Appeal No 12 of 2012 was allowed and the accused's cross-appeal in Criminal Appeal No 4 of 2012 was dismissed by the Court of Appeal.

7. Legal Issues

  1. Diminished Responsibility
    • Outcome: The court found that the defendant's diminished responsibility applied to two of the murder charges but not the third.
    • Category: Substantive
    • Sub-Issues:
      • Abnormality of mind
      • Substantial impairment of mental responsibility
      • Causal link between abnormality of mind and actions
  2. Murder
    • Outcome: The court found the defendant guilty of murder under s 300(a) of the Penal Code for one of the charges.
    • Category: Substantive
    • Sub-Issues:
      • Intention to cause death
      • Causation of death
  3. Culpable Homicide
    • Outcome: The court found the defendant guilty of culpable homicide not amounting to murder for two of the charges.
    • Category: Substantive
    • Sub-Issues:
      • Act causing death
      • Lack of intention for murder

8. Remedies Sought

  1. Conviction for Murder
  2. Death Penalty

9. Cause of Actions

  • Murder
  • Culpable Homicide

10. Practice Areas

  • Criminal Litigation
  • Homicide Defense

11. Industries

  • No industries specified

12. Cited Cases

Case NameCourtAffirmedCitationJurisdictionSignificance
Ong Pang Siew v Public ProsecutorCourt of AppealYes[2011] 1 SLR 606SingaporeRestated the three-limb test which an accused must satisfy in order to establish the defence of diminished responsibility.
Chua Hwa Soon Jimmy v PPN/AYes[1998] 1 SLR(R) 601SingaporeEstablished that the appellant bears the burden of proving the defence of diminished responsibility on a balance of probabilities.
Took Leng How v PPN/AYes[2006] 2 SLR(R) 70SingaporeReiterated the three-limb test which an accused has to satisfy to establish the defence of diminished responsibility.
Khoo James and another v Gunapathy d/o Muniandy and another appealN/AYes[2002] 2 SLR(R) 414SingaporeThe experts' conclusion should not fly in the face of proven extrinsic facts.
G Krishnasamy Naidu v Public ProsecutorN/AYes[2006] 4 SLR(R) 874SingaporeThe three-stage test for the defence of diminished responsibility is essentially a composite one.
Public Prosecutor v Juminem and anotherN/AYes[2005] 4 SLR(R) 536SingaporeThe phrase “substantially impairs his mental responsibility” in the defence of diminish responsibility had has no precise definition.
Regina v LloydN/AYes[1967] 1 QB 175N/ADefinition of substantial does not mean total, that is to say, the mental responsibility need not be totally impaired, so to speak, destroyed altogether. At the other end of the scale substantial does not mean trivial or minimal.
Zailani bin Ahmad v PPN/AYes[2005] 1 SLR(R) 356SingaporeWhether an accused’s mental responsibility was substantially impaired is ultimately a question to be decided by the court based on all the evidence before it.
Sakthivel Punithavathi v Public ProsecutorN/AYes[2007] 2 SLR(R) 983SingaporePrinciples governing a trial judge’s evaluation of conflicting expert testimony.
Saeng-Un Udom v PPN/AYes[2001] 2 SLR(R) 1SingaporeA judge is not entitled to substitute his own views for those of an uncontradicted expert’s.

13. Applicable Rules

Rule Name
No applicable rules

14. Applicable Statutes

Statute NameJurisdiction
Penal Code, Chapter 224Singapore
s 302 of the Penal CodeSingapore
s 307(1) of the Penal CodeSingapore
s 300 of the Penal CodeSingapore
s 300 of the Penal Code, Exception 7Singapore
Criminal Procedure Code (Cap 68, 1985 Rev Ed)Singapore
s 121 of the Criminal Procedure Code (Cap 68, 1985 Rev Ed)Singapore
s 122(6) of the Criminal Procedure Code (Cap 68, 1985 Rev Ed)Singapore

15. Key Terms and Keywords

15.1 Key Terms

  • Diminished Responsibility
  • Adjustment Disorder
  • Mens Rea
  • Culpable Homicide
  • Frenzy
  • Mental Responsibility
  • Multiple Stressors
  • Prolonged Depressive Reaction

15.2 Keywords

  • Murder
  • Diminished Responsibility
  • Adjustment Disorder
  • Singapore
  • Criminal Law
  • Homicide
  • Mental Disorder

17. Areas of Law

Area NameRelevance Score
Diminished Responsibility99
Criminal Law95
Evidence Law70
Criminal Procedure60
Sentencing50
Civil Procedure30

16. Subjects

  • Criminal Law
  • Homicide
  • Diminished Responsibility
  • Mental Health