Why is Insanity an Exempting Circumstance | Imbecility Included
  • Home
  • /
  • Blog
  • /
  • Why is Insanity an Exempting Circumstance | Imbecility Included

Imbecility and Insanity: Grounds for Escaping Criminal Liability

Why is insanity an exempting circumstance, imbecility included? Not all individuals who commit a crime automatically assumes criminal liability. Just like the justifying circumstances found in Article 11 of the Revised Penal Code, which are tantamount to the admission of the commission of the crime and at the same time to the avoidance of criminal liability.

Article 12 of the same code also provides the similar protection and defense to the accused. It provides grounds for the exemption of an individual from punishment as there is wanting in the accused any of the conditions that will make an act voluntary or negligent, thereby absolving him or her from criminal liability. It must be noted, however, that although the accused may escape criminal liability, he or she cannot actually escape civil liability.

Paragraph 1 of the said article provides two (2) circumstances under which an individual may be exempt from criminal liability: 1] insanity; and 2] imbecility.

The Law | Why is insanity an exempting circumstance, and imbecility?

The provision reads:

Article 12. Circumstances which exempt from criminal liability. – the following are exempt from criminal liability:1

1] An imbecile or an insane person, unless the latter has acted during a lucid interval.2

When the imbecile or an insane person has committed an act which the law defines as a felony (delito), the court shall order his confinement in one of the hospitals or asylums established for persons thus afflicted, which he shall not be permitted to leave without first obtaining the permission of the same court.3


An imbecile is exempt in all cases, while an insane is exempt if and only if can be proved that he did not commit the crime during lucid interval. An insane person, during lucid interval, can still act with intelligence.4

Considering that there is a presumption of sound mind as provided in Article 800 of the Civil Code, it is the accused who has the burden of proof to show that he or she was either imbecile or insane when the crime was committed. The law provides the following:

“The law presumes that every person is of sound mind, in the absence of proof to the contrary.”5 The claim of insanity or imbecility must be adequately demonstrated. Furthermore, the law presumes that all activities are voluntarily. It is incorrect to assume that acts were carried out unconsciously.


As defined in Section 1039 of the Revised Administrative Code, insanity is “a manifestation in language or conduct of disease or defect of the brain, or a more or less permanently diseased or disordered condition of the mentality, functional or organic, and characterized by perversion, inhibition, or disordered function of the sensory or of the intellective faculties, or by impaired or disordered volition”6 An insane person, then, is one who has unsound mind or suffers from a mental disorder.7

The following illnesses are covered by the term insanity: dementia praecox, schizophrenia, epilepsy, somnambulism, and malignant malaria. On the other hand, the following are not to be equated with insanity: pedophilia, amnesia, and gay panic syndrome.

The Court held in People vs. Ambal,8 citing Durham vs. U.S,9 that “an accused is not criminally responsible if his unlawful act is the product of a mental disease or a mental defect. A mental disease relieving an accused of criminal responsibility for his unlawful act is a condition considered capable of improvement or deterioration; a mental defect having such effect on criminal responsibility is a condition not considered capable of improvement or deterioration, and either congenital, or the result of injury or of a physical or mental disease.”10

This exempting circumstance, however, is not absolute because there is a presumption of sanity. In People vs. Haloc,11 the Court elucidated that the exemption from criminal liability by virtue of sanity is rooted from the complete absence of intelligence or free will in the performance of the act. It is thus an admission and avoidance.

In People vs. Bascos,12 the Court held that “when a defendant in criminal cases interposes the defense of mental incapacity, the burden of establishing that fact rests upon him.”13 The invocation of this defense is tantamount to the admission of the commission of the crime. It is, thus, the burden of the defense to prove, by clear and convincing evidence, that the accused was insane when the crime was committed. If it can be shown that an individual committed a crime during lucid interval, then said individual is liable for the crime committed.

As held in the case of People vs. Cruz14 and People vs. Renegado,15 in order that insanity may be taken as an exempting circumstance, there must be complete deprivation of intelligence in the commission of the act or that the accused acted without the least discernment. Mere abnormality of his mental faculties does not exclude imputability.16

In People vs Marzan,17 the Supreme Court, in affirming the decision of the RTC, held that even assuming arguendo that the accused manifested abnormal behavior immediately preceding and at the time of the stabbing incident, which may be indicative of an aberrant behavior, cannot be equated to a total deprivation of will or an absence of the power to discern. The accused may even be said to be sane during that time by virtue of him being able to hold his mother after falling on the ground.18

Likewise, in People vs. Renegado,19 the Court also did not give credence to the following testimonies of the accused’s wife to prove the state of insanity of her husband: her husband at times manifests unusual behavior by lashing at his children, tearing off the mosquito net if not properly tied, boxing her, among others. At best, said behaviors are merely proof that the husband is of violent temper and are not proof that the husband is actually insane.20


In People vs. Ambal,21 citing the Codigo Penal,22 an imbecile was defined as a person marked by mental deficiency. Basically, an imbecile is one who, while advanced in age, has a mental development comparable to that of a child between two (2) and seven (7) years of age. He is one who is deprived complete of reason or discernment and freedom of the will at the time of committing the crime.23

To put it simply, this condition or predisposition has no lucid intervals. As such, this is exempting under any circumstances because an imbecile is deprived completely with reason or discernment and freedom of the will at the time of the commission of the crime.24

Being a feebleminded, however, is not equivalent to being an imbecile as held in the case of People vs. Formigones.25 In this case, the man, who, because of jealousy, took violent measures to the point of killing his wife to vindicate his honor, cannot be regarded as an imbecile. It must be noted that feeblemindedness is not exempting, in this case because the offender could distinguish right from wrong. An imbecile or an insane cannot.


All in all, the exempting circumstance of imbecility and insanity is not lightly inferred. The defense must prove, by clear and convincing evidence, that the accused was really suffering from imbecility and insanity at the time he or she committed the crime considering that the presumption is always in favor of sanity. There must be a complete deprivation of intelligence, reason, and discernment on the part of the accused to avail of this exempting circumstance. Otherwise, the accused cannot escape criminal liability, and he or she shall face the consequences of his or her actions.


  1. Article 12, Revised Penal Code[]
  2. Article 12, Paragraph 1, Revised Penal Code[]
  3. Id.[]
  4. Reyes, The Revised Penal Code: Criminal Law Book One [2021][]
  5. Article 800, Civil Code[]
  6. Section 1039 of the Revised Administrative Code of 1917[]
  7. Viada, Codigo Penal, 4th Ed., p. 92[]
  8. G.R. No. L-52688, October 17, 1980[]
  9. 214 F.2d 862 (D.C. Cir. 1954[]
  10. G.R. No. L-52688, October 17, 1980[]
  11. G.R. No. 227312, September 5, 2018[]
  12. G.R. No. 19605, December 19, 1922[]
  13. Ibid.[]
  14. G.R. Nos. L-13219-20, August 31, 1960[]
  15. G.R. No. L-27031. May 31,1974[]
  16. Ibid.[]
  17. G.R. No. 207397, September 24, 2018[]
  18. Ibid.[]
  19. G.R. No. L-27031, May 31,1974[]
  20. Ibid.[]
  21. G.R. No. L-52688, October 17, 1980[]
  22. Viada, Codigo Penal, 4th Ed., p. 92[]
  23. People vs. Nuñez, G.R. Nos. 112429-30. July 23, 1997[]
  24. People vs. Ambal, G.R. No. L-52688. October 17, 1980[]
  25. G.R. No. L-3246, November 29, 1950[]

RALB Law | RABR & Associates Law Firm

Leave a Reply

Your email address will not be published. Required fields are marked

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

You cannot copy content of this page