In the Philippine criminal justice system, the age of an accused is not merely a biographical detail—it is a jurisdictional fact. Under Republic Act No. 9344 (the Juvenile Justice and Welfare Act of 2006, as amended by R.A. 10630), the determination of age dictates whether an individual is subject to the full rigor of adult criminal procedure or entitled to the protective mantle of the juvenile justice system.

While a Certificate of Live Birth (COLB) issued by the Philippine Statistics Authority (PSA) is the "gold standard" of proof, there are instances where police, prosecutors, or the court may reject it due to discrepancies, signs of tampering, or late registration. When the primary document fails, the law provides a clear hierarchy of alternative evidence.

1. The Presumption of Minority

The foundational principle in Philippine law is the Presumption of Minority. If there is any doubt as to the age of the person at the time of the alleged offense, the person shall be presumed to be a child.

Legal Mandate: The burden of proof does not lie with the child to prove they are a minor; rather, if the prosecution or the police claim the individual is an adult, they must overcome this legal presumption with competent evidence.

2. The Hierarchy of Proof

When a birth certificate is unavailable, rejected, or contested, Section 7 of R.A. 9344 (as reinforced by the Supreme Court’s Revised Rule on Children in Conflict with the Law) establishes the following order of preference for proving age:

A. Primary Documentary Evidence

If the PSA Birth Certificate is rejected (perhaps due to a clerical error), the following are considered high-authority substitutes:

Baptismal Certificate: A traditional and often accepted record, provided the date of birth is explicitly stated and the record was created near the time of the event.
School Records: Form 137 or enrollment records from early childhood education.
Passport: A valid government-issued passport is generally considered conclusive.

B. Secondary Evidence: Testimonial Proof

If no documents exist, the court relies on the testimony of people who have personal knowledge of the child's birth. This includes:

Testimony of the Parents: The most direct form of testimonial evidence.
Testimony of the Accused: The minor may testify to their own age.
Testimony of Relatives or Midwives: Anyone present at the birth or who has known the child since infancy.

C. Physical and Circumstantial Evidence

In the absence of any records or reliable witnesses, the "physical appearance" and other circumstantial factors are evaluated.

Physical Manifestations: The court observes the physical features, gait, and demeanor of the accused.
Dental and Bone Scans: While used in some jurisdictions, Philippine courts treat medical age assessments (like X-rays or dental aging) with caution. They are considered indicative rather than conclusive, as biological development varies significantly among individuals.

3. Grounds for Rejecting a Birth Certificate

Why would a prosecutor or the police reject a birth certificate? Common reasons include:

Late Registration: If the birth was registered years after the fact (especially if registered after the criminal charges were filed), it is often viewed with suspicion as a "manufactured" defense.
Facial Inconsistencies: If the person claiming to be 14 years old possesses physical characteristics (e.g., facial hair, muscular build) that strongly suggest they are much older.
Alias Discrepancies: When the name on the birth certificate does not match the name the accused used during the arrest or in previous school/employment records.

4. Remedial Steps: What to do if Rejected

If the police or prosecutor refuses to recognize the accused as a minor, the following steps are typically taken:

Manifestation for Age Determination: The defense counsel must immediately file a motion before the prosecutor (during inquest/preliminary investigation) or the judge to conduct a summary hearing for age determination.
Social Case Study Report: A Social Worker from the DSWD or the Local Social Welfare and Development Office (LSWDO) will conduct an interview. Their professional assessment of the child’s "discernment" and developmental age carries significant weight in court.
The "Best Interest" Rule: In all proceedings, if the evidence between being an adult or a minor is equally balanced, the court must rule in favor of minority.

5. Consequences of Proving Minority

Successfully proving minority changes the legal landscape immediately:

Immunity from Suit: If the minor is 15 years old or below, they are exempt from criminal liability (though subject to an intervention program).
Discernment Requirement: If the minor is above 15 but below 18, the prosecution must prove they acted with discernment to proceed with a criminal case.
Confidentiality: All records are closed to the public, and the child's identity is protected.

Summary Table: Evidence for Age Determination

Rank	Type of Evidence	Examples
1st	Primary Documents	PSA Birth Certificate, Passport
2nd	Secondary Documents	Baptismal Certificate, School Records (Form 137)
3rd	Testimonial	Statements from parents, siblings, or the attending midwife
4th	Physical/Medical	Visual observation by the judge, DSWD assessment

Would you like me to draft a sample Motion for Age Determination based on these Philippine legal standards?