Introduction

In the Philippines, adultery and concubinage remain criminal offenses under the Revised Penal Code (Act No. 3815, as amended), specifically Articles 333 and 334. These provisions reflect the country's emphasis on protecting the sanctity of marriage and family life, rooted in its cultural and legal traditions influenced by Spanish civil law and Catholic values. Adultery pertains to acts committed by a married woman and her paramour, while concubinage applies to acts by a married man and his mistress. These crimes are classified as "crimes against chastity" and are considered private offenses, meaning they can only be initiated by the offended spouse.

Filing a criminal case for these offenses involves a specific legal process that requires adherence to procedural rules under the Rules of Court and relevant jurisprudence from the Supreme Court. This article provides a comprehensive overview of the definitions, elements, evidentiary requirements, filing procedures, defenses, penalties, and related legal considerations within the Philippine context. It is essential to note that while these laws are still enforceable, there have been ongoing discussions in Congress about potential reforms, such as decriminalization or equalization of penalties between genders, but no such changes have been enacted as of the current legal framework.

Definitions and Distinctions

Adultery (Article 333, Revised Penal Code)

Adultery is committed by a married woman who engages in sexual intercourse with a man who is not her husband. The man who has carnal knowledge of her, knowing her to be married, is also liable, even if the marriage is subsequently declared void. This offense is gender-specific, applying only to married women and their male partners.

Concubinage (Article 334, Revised Penal Code)

Concubinage is committed by a married man in any of the following ways:

Keeping a mistress in the conjugal dwelling.
Cohabiting with her in any other place.
Having sexual intercourse with her under scandalous circumstances.

Like adultery, the offense involves the married man and his female partner (the concubine). The law is also gender-specific, with less stringent requirements for proof compared to adultery, reflecting historical biases in the penal code.

Key distinctions:

Adultery requires proof of sexual intercourse, while concubinage can be established through cohabitation or scandalous circumstances without necessarily proving intercourse.
Penalties for adultery are generally harsher than for concubinage, which has been criticized for gender inequality.
Both offenses require that the offender is legally married at the time of the act, and the marriage must be valid under Philippine law (e.g., not bigamous or void ab initio, though knowledge of marital status is key for the co-accused).

Elements of the Offenses

To successfully prosecute a case, the prosecution must prove the following elements beyond a reasonable doubt:

For Adultery:

The woman is married.
She has sexual intercourse with a man not her husband.
The man knows she is married.

For Concubinage:

The man is married.
He commits any of the acts specified (keeping a mistress in the home, cohabiting elsewhere, or intercourse under scandalous circumstances).
The woman knows he is married (for her liability as concubine).

"Scandalous circumstances" refer to acts that cause public outrage or disgrace, such as open displays of affection or living together notoriously as husband and wife. Jurisprudence, such as in People v. Zapata (G.R. No. L-30411, 1971), emphasizes that mere suspicion is insufficient; direct or circumstantial evidence must establish the acts.

Who Can File the Complaint

Adultery and concubinage are private crimes under Article 344 of the Revised Penal Code. Only the offended spouse (the husband in adultery cases or the wife in concubinage cases) can initiate the criminal action. If the offended spouse is legally incapacitated or deceased, the complaint may be filed by the offended party's parents, grandparents, or guardians, in that order.

Important notes:

The offended spouse must not have consented to or pardoned the act prior to filing.
If both spouses are guilty of similar offenses, neither can file against the other (doctrine of mutual guilt).
The complaint must include both the guilty spouse and the paramour/concubine as accused; prosecuting only one extinguishes the case against the other.

Gathering Evidence

Before filing, the complainant must compile sufficient evidence to establish probable cause. Common types include:

Testimonial evidence: Affidavits from witnesses who saw the acts, such as cohabitation or scandalous behavior.
Documentary evidence: Hotel receipts, text messages, emails, or social media posts indicating the affair.
Physical evidence: Photographs, videos, or DNA tests (e.g., from children born out of the affair, though this is more relevant in civil cases).
Circumstantial evidence: Bank statements showing financial support for the mistress, travel records, or property deeds in the paramour's name.

Under the Anti-Wiretapping Law (Republic Act No. 4200), illegally obtained recordings cannot be used as evidence. However, the Supreme Court's ruling in Zulueta v. Court of Appeals (G.R. No. 107383, 1996) allows spouses to access each other's communications in certain contexts without violating privacy laws. It is advisable to consult a lawyer to ensure evidence is admissible.

Prescription period: The crimes prescribe in 15 years from discovery (Article 90, RPC), but the complaint must be filed within one year from discovery if the offended spouse consents or pardons afterward.

Step-by-Step Procedure for Filing the Case

Step 1: Consultation with a Lawyer

Engage a private lawyer or seek assistance from the Public Attorney's Office (PAO) if indigent. The lawyer will help draft the complaint-affidavit and assess the strength of the case.

Step 2: Filing the Complaint-Affidavit

Prepare a sworn complaint-affidavit detailing the facts, elements, and evidence.
File it with the Office of the City or Provincial Prosecutor in the place where the offense was committed (territorial jurisdiction under Rule 110, Rules of Court).
Pay the necessary filing fees (minimal for criminal cases).
The complaint must be subscribed before the prosecutor or a notary public.

Step 3: Preliminary Investigation

The prosecutor conducts a preliminary investigation to determine probable cause.
The respondents (accused) are subpoenaed to submit counter-affidavits.
Replies and rejoinders may be exchanged.
If probable cause is found, the prosecutor files an Information with the Municipal Trial Court (MTC) or Regional Trial Court (RTC), depending on the penalty (RTC for penalties exceeding 6 years).
If no probable cause, the case is dismissed, but the complainant can appeal to the Department of Justice (DOJ).

Step 4: Arraignment and Pre-Trial

The accused are arraigned and enter a plea (guilty or not guilty).
Pre-trial conference addresses stipulations, evidence marking, and possible plea bargaining.

Step 5: Trial

The prosecution presents evidence first, followed by the defense.
Witnesses are examined and cross-examined.
The court renders a judgment based on proof beyond reasonable doubt.

Step 6: Appeal

If convicted, the accused can appeal to the Court of Appeals, then the Supreme Court.
Acquittal is final and cannot be appealed by the prosecution (double jeopardy).

The entire process can take 1-5 years, depending on court backlog.

Defenses and Extinguishment of Liability

Common defenses:

Lack of marriage validity (e.g., bigamous marriage).
Absence of knowledge of marital status by the paramour/concubine.
Insufficient evidence of sexual intercourse or scandalous circumstances.
Alibi or denial supported by evidence.

Liability extinguishes if:

The offended spouse expressly or impliedly consents to the act.
The offended spouse pardons the offenders (must be express and prior to trial).
The guilty spouse dies before final judgment.
Prescription lapses.

Under Article 344, RPC, pardon must be given to both offenders; pardoning only one does not extinguish the case.

Penalties

For Adultery:

Prision correccional in its medium and maximum periods (2 years, 4 months, and 1 day to 6 years) for both the wife and paramour.

For Concubinage:

Prision correccional in its minimum and medium periods (6 months and 1 day to 4 years and 2 months) for the husband.
Destierro (banishment) for the concubine.

Additional penalties may include civil liability for moral damages. If a child is born from the affair, it affects legitimacy and support obligations under the Family Code.

Related Legal Considerations

Civil Implications: Filing a criminal case does not preclude civil actions for legal separation (Article 55, Family Code), annulment, or damages. Evidence from the criminal case can be used in family court.
VAWC Overlap: If the affair involves psychological violence, it may fall under Republic Act No. 9262 (Anti-Violence Against Women and Their Children Act), allowing for protection orders.
Gender Equality Issues: The laws have been challenged for violating equal protection (e.g., in Estrada v. Escritor, A.M. No. P-02-1651, 2003), but remain valid. Bills like House Bill No. 6029 seek to decriminalize or equalize penalties.
Jurisdictional Notes: For overseas Filipinos, jurisdiction applies if the offense affects Philippine interests (extraterritorial application under Article 2, RPC).
Amnesty or Pardon: Presidential pardon can be sought post-conviction, but not for private crimes without the offended spouse's consent.
Alternative Dispute Resolution: Mediation is not typically available for criminal cases, but amicable settlement can lead to desistance.

Challenges and Practical Advice

Proving these cases is difficult due to the private nature of the acts, often relying on circumstantial evidence. Public scandal can strengthen a case but may lead to social stigma. Complainants should prioritize emotional support and consider the impact on children.

In summary, filing a criminal case for adultery or concubinage requires meticulous preparation, adherence to procedural rules, and a clear understanding of the legal elements. While these laws uphold marital fidelity, they also highlight evolving societal views on gender and privacy in the Philippines.