Accused-appellant implores this Court to admit the possibility that his first-born daughter had simply concocted a false accusation of three counts of rape against him upon the instigation of the mother, for which crimes he, upon final conviction, may be made to live behind bars for the rest of his life. This proposition defies rhyme and reason and is, therefore, rather difficult to accept. We are not ready to substitute the conviction in this case for an acquittal.

Three separate Informations were filed before the court a quo which charged three counts of rape against accused-appellant committed against his 15-year-old-daughter Ronalyn Magpantay, in May, June, and July 1991 as follows:

CRIMINAL CASE NO. 1152-M

That in or about the month of May, 1991 in the Municipality of Tanay, Province of Rizal, Philippines and within the jurisdiction of this Honorable Court, the above-named accused, by means of force and intimidation, did then and there, wilfully and unlawfully and feloniously succeeded in having carnal knowledge with his own daughter Ronalyn Magpantay y Montales against her will and consent.

(p. 1, Record, Crim. Case No. 1152-M.)

CRIMINAL CASE NO. 1153-M
That on or about the 28th day of June, 1991 in the Municipality of Tanay, Province of Rizal, Philippines and within the jurisdiction of this Honorable Court, the above-named accused, by means of force and intimidation, did then and there wilfully, unlawfully and feloniously succeeded in having carnal knowledge with his own daughter Ronalyn Magpantay y Montales against her will and consent.

(p. 1, Record, Crim. Case No. 1153-M.)

CRIMINAL CASE NO. 1154-M
That on or about the 3rd day of July, 1991 in the Municipality of Tanay, Province of Rizal, Philippines and within the jurisdiction of this Honorable Court, the above-named accused, by means of force and intimidation, did then and there wilfully, unlawfully and feloniously succeeded in having carnal knowledge with his own daughter Ronalyn Magpantay y Montales against her will and consent.

(p. 1, Record, Crim. Case No. 1154-M.)

At the arraignment conducted on September 1, 1992, accused-appellant pleaded not guilty. From the evidence presented during the joint trial of the three cases, the trial court summarized the prosecution's version as follows:

One day in the month of May 1991 while Estrella Magpantay was at her place of work weeding in a caingin, accused instructed Ronalyn's younger brother and sisters to get out of the house and while outside, accused got a knife, pocked it at the neck of Ronalyn and then directed her to undress. With the knifed pocked at her neck and at the same time threatening to kill her she removed her T-shirt and short leaving her bra and panty on. Accused began kissing Ronalyn on the cheek, lips, breast and her private organ with the knife still poked on her neck while his left hand was removing the bra and panty. After removing the panty, accused inserted his private organ into Ronalyn's vagina and while being inserted, Ronalyn felt pains. After finishing the sexual act, he instructed Ronalyn to dress up and warned her not to tell anybody including the mother or else they will be killed.

Then on June 28, 1991 Ronalyn was again sexually abused with the use of a knife, followed on July 3, 1991.

On July 3, 1992, the mother of Ronalyn and one of the children left their house to wash clothes in a river. Left in the house were the accused, Ronalyn and the three small children. At around 10:00 o'clock in the morning, accused instructed the brother and two sisters of Ronalyn to bring food to their mother. Accused and Ronalyn were the ones left in the house. Accused with a knife poked at Ronalyn's neck instructed her to remove her clothes. She tried to refuse but cannot do anything. She reluctantly removed her clothes and after removing them, accused took off the bra and panty. He started touching Ronalyn's private organ and kissed it. Thereafter, accused inserted his penis into the private organ of Ronalyn. After finishing the sexual act, he told Ronalyn to dress up. This time her brother Michael saw them but left for fear of the accused.

The incident of June 28, 1991 was seen by the mother of Ronalyn while the July 3, 1991 incident was seen by Michael. Ronalyn's mother corroborated her testimony. Dr. Vladimir E. Villaseñor of the PNP Laboratory Service, Camp Crame, Quezon City, upon examining the genitalia of Ronalyn shows healed lacerations at 9:00 o'clock, 3:00 o'clock, 5:00 o'clock, and 6:00 o'clock (Exhibit "C").

(pp. 81-82, Record.)

After due proceedings, a judgment of conviction dated October 22, 1993 was rendered by the Regional Trial Court of the Fourth Judicial Region (Branch 79) stationed at Morong, Rizal, disposing as follows:

1. WHEREFORE, accused Teotimo Magpantay is hereby sentenced:
   
   
2. in Criminal Case No. 1152 to suffer the penalty of Reclusion Perpetua and to indemnify Ronalyn Magpantay the sum of P50,000.00;
   
   
3. in Criminal Case No. 1153 to suffer the penalty of Reclusion Perpetua and to indemnify Ronalyn Magpantay the sum of P50,000.00; and
   
   
4. in Criminal Case No. 1154 to suffer the penalty of Reclusion Perpetua and to indemnify Ronalyn Magpantay the sum of P50,000.00.
   
   SO ORDERED.
   
   
   (p. 85, Record.)

Upon the filing of a Notice of Appeal dated November 16, 1993, the lower court ordered the elevation of the record of the case to this Court, but, because the same could not be completed, some of the transcripts of stenographic notes having been destroyed when the old court room housing Branch 79 was burned down, the Court ordered said regional trail court to retake the testimony of the witnesses who testified during the hearings on the dates of the missing transcripts. Upon completion of the transcripts on October 16, 1996, accused-appellant was ordered to file his brief with which he complied on March 14, 1997. The appellee's brief was filed on October 15, 1997. On November 6, 1997, counsel for accused-appellant manifested that no reply brief is intended to be filed. The case is now ripe for decision after some delay through no fault of anybody.

Accused-appellant assigns a single alleged error bearing on his alibi, which according to him is the only available defense. However, in the four-page argument portion of his brief, accused-appellant assails the credibility of witness Estrella Montales Magpantay, the victim's mother, and the expert witness, Dr. Vladimir Villaseñor of the PNP Crime Laboratory Services, without making any point on the matter of alibi, which the trial court allegedly disregarded.

In law, the term alibi has a specific technical meaning. It is a plea of having been elsewhere than at the place of the commission of the crime at the time of its commission. The requisite elements for alibi to be appreciated are: (a) to prove his presence at another place at the time of the perpetration of the offense and (b) to demonstrate that it would thus be physically impossible for him to be at the scene of the crime. (People vs. Dayson, 242 SCRA 124 [1995]).

Accused-appellant apparently used the term alibi in its loose meaning which is as an excuse offered for the exoneration from an offense. Thus, he strikes at the credibility of Estrella Magpantay, his wife and the victim's mother. He insists that the accusations hurled against him are mere concoctions of his wife, Estrella, to get even with him after he caught her committing an act of infidelity in flagrante delicto.

We do not subscribe to accused-appellant's arguments. We are inclined to affirm the judgment of conviction in toto, considering that the basic principles applicable to the case at bench clearly militate against accused-appellant's position, which pertains essentially to credibility of witnesses.

Well-settled is the principle that the assessment of the credibility of witness and their testimony is a matter best left to the trial court because of its unique opportunity to observe the witnesses firsthand and note their demeanor, conduct, and attitude under grilling examination (People v. Ombrog, G.R. No. 104666, February 12, 1997).

Obviously aware of this principle, the trial court became true to its role in assessing the credibility of witnesses and paid close attention to the demeanor of the principal witness, the victim herself. Observations such as these cannot be gleaned from the pages of the transcript of stenographic notes which are all that are available to this Court upon review. Thus, we find relevance in the trial court's factual findings, to wit:

Complainant Rosalyn Magpantay was fifteen (15) years old in May 1991 when sexually abused for the first time by her own father who is the accused in these cases. She has not started experiencing her monthly sickness (tsn. page 13, January 6, 1993). The narration made by Ronalyn of how she was raped by her own father first in May, then on June 28, and the third on July 3, all in 1991 appears credible and worthy of belief. The court noted that while testifying she answers questions asked of her both in direct and cross-examination in a straight forward manner, often times with tears on her eyes and more often than not with a disdain look towards her father. She appears no longer humiliated and embarrassed in narrating all that were necessary only to show that she was raped. She is young, decent, shy and soft-spoken. She is not the type of a woman who will admit before the eyes of the public that she has been criminally ravished if there is no truth to what she was narrating, for her natural instinct would be to protect her honor . . . .

(pp. 82-83, Record.)

The trial court correctly applied our ruling in the case of People vs. Caballes (199 SCRA 152 [1991]) where we held:

Given complainant's naivete and inexperience in matters of sexuality, it was improbable that she would fabricate matters about rapes committed against her person and concoct lies against her own father, knowing fully well the seriousness of such charges, even granting that she harbored abhorrence for his ways, and run the risk of subjecting herself to humiliating and embarrassing scrutiny wrought by a public trial. We have repeatedly held that when a woman testifies that she has been raped, she says all that is necessary to signify that the crime has been committed. For no young decent Filipina woman would publicly admit that she had been criminally ravished unless that is the truth, for her natural instinct is to protect her honor, and unless motivated by an honest desire to seek justice.

(p. 164.)

It is not easy to convince a young girl such as Ronalyn, then only fifteen years of age, to have herself physically examined and thereafter undergo the ordeals of a public trial for rape against her very own father if she was not motivated by her desire to seek justice. In People vs. Sanchez (250 SCRA 14 [1995]), the Court ruled:

. . . no woman especially one who is of tender age would concoct a story of defloration, allow an examination of her private parts and thereafter permit herself to be subjected to a public trial, if she is not motivated solely by the desire to have the culprit apprehended and punished.

(p. 23.)

The trial court's findings based on the evidence presented by the accused-appellant for his desire is likewise given great respect by this Court. There is no indication that the trial court erred in refusing to give credence to the alleged motive of accused-appellant's wife to concoct such an accusation of rape against him. The trial court correctly found accused-appellant's claim in this regard to be highly preposterous and unworthy of belief. Testimonial evidence is weighed in accordance with the standard used. In People vs. Baquiran (20 SCRA 451 [1967]), where we held:

. . . It is a legal truism that evidence to be believed, must not only proceed from the mouth of a credible witness, but must be credible in itself. Human perception can be warped by the impact of events and testimony colored by the unconscious workings of the mind. No better test has yet been found to massacre the value of a witness' testimony than its conformity to the knowledge and common experience of mankind. . . .

(p. 454.)

The alibi referred to by the accused-appellant in his brief consists in his having his caught his wife in flagrante delicto having sex with another person inside their bathroom. This was followed by a heated argument between the spouses which included physical violence as well. According to accused-appellant, his wife left the conjugal dwelling that night with a threat that she would do everything in order to make him pay for what he did. In plain and simple words, accused-appellant wants to impress upon the Court that his wife made good her threat by pressing charges for rape. This means convincing her daughter to concoct the story of rape, to force her to allow the physical examination of her private parts, and to undergo the trauma of a public trial all this in order to put away accused-appellant and make him rot in jail for the rest of his life. This is very hard for this Court to believe. The dictum which states that "blood is thicker than water" is still very true in the Filipino culture. It is inconceivable that Ronalyn would falsely point an accusing finger at her own father for a crime as serious as rape only to please her mother. This is plainly incredible.

WHEREFORE, premises considered, the conviction by the trial court for all three cases are hereby AFFIRMED in toto. No costs.

SO ORDERED.

Narvasa, C.J., (Chairman), Romero, Francisco, and Panganiban, JJ., concur.