G.R. No. L-49162 - Jao vs. Court of Appeals

Petitioner: Janice Marie Jao, a minor represented by her mother and guardian ad litem, Arlene S. Salgado, seeking recognition and support.
Respondents: The Honorable Court of Appeals and private respondent Perico V. Jao, who denied paternity.

On October 28, 1968, Janice (through her guardian) filed an action for recognition and support at the Juvenile and Domestic Relations Court.
The trial court relied initially on a blood grouping test conducted by the National Bureau of Investigation (NBI) but, after a second motion for reconsideration by the petitioner, ordered a trial on the merits which ultimately declared Janice as the child of Jao.
Jao appealed the trial court’s decision, emphasizing the weight of the blood test results as conclusive evidence of non-paternity.

The NBI conducted a series of six blood grouping tests on January 21, 1969, using two recognized systems: the MN Test and the ABO System.
The results definitively indicated that the blood type of Janice was not compatible with that of an offspring from a union between her mother, Arlene, and Perico V. Jao.
The tests were performed under proper safeguards and witnessed by experts, including a knowledgeable serologist, Dr. Lorenzo Sunico, whose findings were consistent and approved.

Claimed to have first met Jao in the third or fourth week of November 1967 at the Saddle and Sirloin, Bayside Club.
Asserted that their first sexual intercourse occurred on November 30, 1967, at her residence, with cohabitation beginning after December 16, 1967 following a cruise to Mindoro Island.

Admitted meeting ARLENE at the club but maintained the encounter occurred on December 14, 1967.
Claimed that his first sexual encounter with ARLENE took place on or about January 18, 1968, with cohabitation starting only in May 1968 at a different location.

These conflicting narratives were significant because the timing of sexual intercourse and cohabitation was central to establishing whether paternity could be presumed by acts of recognition.

Despite cohabiting with Arlene and providing for her during the pregnancy, Jao’s later actions—specifically his petition to delete his name from Janice’s birth certificate—demonstrated a clear repudiation of paternity.
Testimonies revealed that, at the critical time of conception, Arlene had been involved with another man, Melvin Yabut, who was the intermediary introducing her to Jao, as well as a third party referred to as “Oying” Fernandez.
The credibility of ARLENE’s testimony was questioned due to inconsistencies and concerns regarding her reliability despite the trial court’s earlier favorable observations of her candor.

Petitioner sought to discredit the conclusiveness of the blood grouping tests by questioning the qualifications of the NBI personnel and the scientific methodology employed.
It was argued that blood tests have probative value only when affirming paternity and not when used to establish non-paternity.
In contrast, established scientific opinion holds that while such tests might not conclusively prove paternity, a negative result is conclusive in disproving the alleged father’s paternity.

Whether the blood grouping tests conducted by the NBI are admissible as conclusive evidence in proving non-paternity in this case.
Whether the conflicting accounts concerning the timing of sexual intercourse and cohabitation between Jao and ARLENE should override the scientifically established results of the blood tests.
Whether Jao’s pre- and post-birth actions, including his avoidance of recognition and administrative steps to repudiate paternity, can be credited over the negative blood test findings.