During my freshman year in law school, the criminal law doctrine that amazed me the most is the principle of mistake of fact. As defined and discussed in the book of Justice Luis B. Reyes, Revised Penal Code – Criminal Law, mistake of fact is a misapprehension of fact on the part of the person who caused injury to another. He is not, however, criminally liable, because he did not act with criminal intent. The requisites of mistake of fact as a defense are as follows: (a) that the act done would have been lawful had the facts been as the accused believed them to be; (b) That the intention of the accused in performing the act should be lawful; (3) That the mistake be without the fault or carelessness on the part of the accused.
US vs Ah Chong[1] is the most famous case discussing this doctrine. The facts of the case, to wit: Ah Chong and Pascual Gualberto, both employed at Officers’ quarters No. 27, Fort Mc Kinley, lived in a detached house situated some 40 meters from the nearest building. No one slept in the house except the two, who jointly occupied a small room toward the rear of the building, the door of which opened upon a narrow porch running along the side of the porch was covered by a heavy growth of vines for its entire length and height. The door of the room was not furnished with a permanent lock, and occupants, as a measure of security, had attached a small hook on the inside of the door, and were in the habit of reinforcing this somewhat insecure means of fastening the door by placing against it a chair. In the room there was but one small window, which, like the door, opened on the porch. Aside from the door and window, there were no other openings of any kind in the room.
On the night of August 14, 1908, at about 10 o’clock, Ah Chong, who had received for the night, was suddenly awakened by someone trying to force open the door of the room. He sat up in bed and called out twice, “Who is there?” He heard no answer and was convinced by the noise at the door that it was being pushed open by someone bent upon forcing his way into the room. Due to the heavy growth of vines along the front of the porch, the room was very dark, and the defendant, fearing that the intruder was a thief, leaped to his feet and called out. “If you enter the room, I will kill you.” At that moment he was struck just above the knee by the edge of the chair which had been placed against the door. In the darkness and confusion the defendant thought that the blow had been inflicted by the person who had forced the door open, who he supposed to be a burglar, though in the light of after events, it is probable that the chair was merely thrown back into the room by the sudden opening of the door against which it rested. Seizing a common kitchen knife which he kept under his pillow, the defendant struck out wildly at the intruder who, it afterwards turned out, was his roommate, Pascual. Pascual ran out upon the porch and fell down on the steps in a desperately wounded condition, followed by the defendant, who immediately recognized him in the moonlight. Seeing that Pascual was wounded, he called to his employers who slept in the next house, No. 28, and ran back to his room to secure bandages to bind up Pascual’s wounds.
There had been several robberies in Fort McKinley not long prior to the date of the incident just described, and as Ah Chong alleges, it was because of these repeated robberies he kept a knife under his pillow for his personal protection. The deceased and the accused, who roomed together and who appear to have on friendly and amicable terms prior to the fatal incident, had an understanding that when either returned at night, he should knock at the door and acquaint his companion with his identity. Also, when police officers arrived to the place Ah Chong then and there admitted that he stabbed his roommate, but said that he did it under the impression that Pascual was a thief because he forced open the door of their sleeping room, despite defendant’s warning.
The trial court convicted Ah Chong for homicide, however, the Supreme Court reversed said convicted and acquitted Ah Chong. In acquitting Ah Chong, the Supreme Court elucidated: A careful examination of the facts as disclosed in the case at bar convinces us that the defendant Ah Chong struck the fatal blow in the firm belief that the intruder who forced open the door of his sleeping room was a thief, from whose assault he was of imminent peril, both of his life and of his property; that in view of all the circumstances, as they must have presented themselves to the defendant at the time, he acted in good faith, without malice, or criminal intent, in the belief that he was doing no more than exercising his legitimate right of self-defense; that had the facts been as he believed them to be he would have been wholly exempt from criminal liability on account of his act; and that he cannot be said to have been guilty of negligence or recklessness or even carelessness in falling into his mistakes as to the facts, or in the means adopted by him to defend himself from the imminent danger which he believed threatened his person and his property and the property under his charge.
Since evil intent is in general an inseparable element in every crime, any such mistake of fact as shows the act committed to have proceeded from no sort of evil in the mind necessarily relieves the actor from criminal liability provided always there is no fault or negligence on his part; and as laid down by Baron Parke, “The guilt of the accused must depend on the circumstances as they appear to him.” That is to say, the question as to whether he honestly, in good faith, and without fault or negligence fell into the mistake is to be determined by the circumstances as they appeared to him at the time when the mistake was made, and the effect which the surrounding circumstances might reasonably be expected to have on his mind, in forming the intent, criminal or otherwise, upon which he acted.
[1] U.S. vs Ah Chong, 15 Phil. 488