1) What “prescription” means in criminal law

In Philippine criminal law, prescription of crimes refers to the time limit within which the State must commence criminal action against an offender. If the prescriptive period lapses before a criminal case is properly commenced, the offense generally becomes time-barred, and the accused may invoke prescription as a defense.

Prescription is different from:

Prescription of penalties (time limit to enforce a sentence after conviction), and
Prescription of civil actions (time limits for damages actions, which can have different rules when pursued independently).

This article focuses on prescription of crimes for:

Rape by sexual assault (often called “sexual assault” in ordinary usage), and
Acts of lasciviousness (under the Revised Penal Code), with notes on frequent child-victim charging under special laws.

2) The governing legal framework

A. Revised Penal Code rules (general)

For felonies under the Revised Penal Code (RPC), three RPC provisions are the backbone:

Article 90 – Prescriptive periods of crimes (how long before the crime prescribes).
Article 91 – When prescription begins to run and how it is interrupted.
Article 93 – Rules for computing prescription (technical computation principles; often read together with Art. 91 and jurisprudence).

B. Special laws (when the charge is not under the RPC)

If the offense is defined and punished by a special penal law (for example, certain child-abuse statutes), courts frequently apply Act No. 3326 (as amended) on prescription, unless the special law provides its own prescriptive rule.

Because many “lascivious conduct” cases involving minors are filed under special laws rather than the RPC, it’s critical to identify what statute is actually charged, since that can change the prescriptive period and the “start” of the clock.

3) Identify the crime correctly: “sexual assault” vs “acts of lasciviousness”

A. “Sexual assault” in Philippine criminal charging usually means rape by sexual assault

Under the RPC (as amended by the Anti-Rape Law), rape can be committed in two principal ways:

Rape by sexual intercourse, and
Rape by sexual assault: insertion of the penis into another person’s mouth or anal orifice, or insertion of any instrument/object into genital or anal orifice, under the circumstances defined by law.

In practice, when people say “sexual assault,” they often mean rape by sexual assault (RPC).

B. “Acts of lasciviousness” is a separate felony

Acts of lasciviousness under the RPC generally covers lewd acts done with violence or intimidation, without the penetration elements that would make it rape.

C. Child-victim cases may be filed under a special law instead

When the offended party is a child, prosecutors sometimes charge “lascivious conduct” or related acts under special laws rather than the RPC. That choice can affect:

the penalty (hence the prescriptive period), and
occasionally the prescription rules (e.g., Act No. 3326).

4) How long is the prescriptive period?

A. The key principle: the prescriptive period depends on the imposable penalty

For RPC felonies, Article 90 sets prescriptive periods based primarily on the classification of the penalty attached to the offense.

A commonly used working map under Article 90 (RPC) is:

20 years – crimes punishable by reclusion perpetua or reclusion temporal
15 years – crimes punishable by other afflictive penalties
10 years – crimes punishable by correctional penalties
5 years – crimes punishable by arresto mayor
2 years – crimes punishable by light penalties
1 year – certain specified offenses like libel and similar offenses (as expressly listed)

You then match the offense’s penalty (as charged and as qualified) to the category above.

5) Prescription for rape by sexual assault (RPC)

A. Baseline penalty → typical prescriptive period

Rape by sexual assault is punished more lightly than rape by sexual intercourse in its basic form. As a result:

If the imposable penalty is correctional (commonly prision mayor) → prescription is typically 10 years.

B. Qualified circumstances can increase the penalty → longer prescriptive period

If the information alleges qualifying circumstances that raise the penalty to reclusion temporal (an afflictive penalty in the 20-year bracket under Article 90), then:

Prescription can become 20 years.

C. Important practice note

What controls prescription is not the label “sexual assault,” but the exact statutory designation and the penalty range for the charged form (basic vs qualified). In close cases, courts look at the information/complaint, the allegations, and the penalty corresponding to those allegations.

6) Prescription for acts of lasciviousness (RPC)

A. Usual penalty classification

Acts of lasciviousness under the RPC is generally punished by a correctional penalty (commonly within prision correccional periods).

If the imposable penalty is correctional → prescription is typically 10 years.

B. Variants and charging choices matter

If the same underlying acts are charged under a special law (e.g., child-protection statutes), the imposable penalty can be higher (sometimes afflictive), which may extend prescription (often to 20 years), and may also change which prescription statute is used (RPC vs Act No. 3326).

7) When does the prescriptive period start running?

A. Default rule: from commission of the crime

As a general principle for RPC crimes, the prescriptive period runs from the day the crime is committed.

B. If the crime is concealed: from discovery

For concealed offenses, the period runs from discovery by:

the offended party,
the authorities, or
their agents.

Practical relevance in sexual offenses: many sexual offenses—especially where threats, coercion, dependency, or fear are present—may surface later. Whether the offense is legally treated as “concealed” can be fact-intensive and often litigated.

C. Interaction with child-victim dynamics

When the offended party is a minor, delayed disclosure is common. Courts may examine:

whether the offender’s control, threats, or relationship effectively concealed the offense,
when the offense became known to parents/guardians/authorities, and
the date the complaint was actually filed.

Because outcomes can hinge on these details, prescriptive-start issues are often decided case-by-case.

8) What interrupts prescription?

A. Interruption by filing of the complaint or information

Under Article 91 (RPC), prescription is generally interrupted by the filing of the complaint or information. In practice, Philippine jurisprudence has treated the proper filing of a complaint that initiates the criminal process (including for preliminary investigation) as an interruption, but the exact contours can depend on the nature of the offense and the forum.

B. What happens after interruption

Once interrupted:

the prescriptive clock stops running while the case is pending. If proceedings terminate without a conviction or acquittal (or are stopped without lawful reason), prescription may run again, subject to the rules on recommencement.

C. Special law cases (Act No. 3326)

For offenses punished by special laws, Act No. 3326 contains its own interruption language. The practical question is often: what filing counts (prosecutor vs court) and when the case is deemed commenced—issues that are shaped by doctrine and the facts of filing.

9) Computing prescription in real life: a step-by-step method

Step 1: Identify the statute of the charge

RPC (rape by sexual assault; acts of lasciviousness), or
Special law (child-abuse-related sexual misconduct; other statutes).

Step 2: Identify whether it is basic or qualified

Read the allegations. Qualifying circumstances can increase the penalty, which can increase the prescriptive period.

Step 3: Determine the imposable penalty classification

reclusion perpetua / reclusion temporal → 20 years
other afflictive → 15 years
correctional → 10 years
etc.

Step 4: Determine the start date

Date of commission, or
Date of discovery (if legally “concealed” and applicable).

Step 5: Check interruption events

Date complaint/information was filed (and where/how it was filed),
Whether the filing was sufficient to commence action for prescription purposes.

Step 6: Count elapsed time net of interruptions

If net elapsed time exceeds the prescriptive period before commencement, prescription may bar prosecution.

10) Common misconceptions and clarifications

Misconception 1: “All rape has the same prescription.”

Not always. Rape by sexual intercourse and rape by sexual assault can carry different penalties; qualified circumstances can also change penalties. Prescription follows the penalty category.

Misconception 2: “Prescription always starts on the date of the incident.”

Not always. If the crime is legally treated as concealed, prescription may start at discovery. The application is fact-sensitive.

Misconception 3: “Filing a blotter entry is the same as filing a case.”

A police blotter or barangay record is not necessarily the “commencement” of criminal action for prescription purposes. The legally meaningful act is typically the filing of a complaint (for preliminary investigation) or an information (in court), depending on the offense and procedural posture.

Misconception 4: “If the victim delays reporting, the case automatically prescribes.”

Delay does not automatically equal prescription. The legal start of prescription, concealment, interruption, and filing dates must be analyzed.

11) Relationship to civil actions for damages

A. Civil liability is commonly pursued with the criminal case

In many sexual offense prosecutions, civil liability (damages) is adjudicated alongside the criminal case.

B. Independent civil actions may have different prescriptive periods

If a civil case is filed independently (for example, under quasi-delict or other Civil Code bases), different prescriptive periods may apply and do not always track the criminal prescription rules. However, when civil liability is anchored on the crime and pursued with it, the fate of the criminal action can heavily affect the civil route.

12) Practical charging patterns in the Philippines

Same conduct, different possible charges. Prosecutors may choose among:
- rape by sexual assault (RPC),
- acts of lasciviousness (RPC),
- special-law child-protection offenses (when the victim is a child), among others.
Prescription hinges on the final charge and its penalty. Two cases with similar facts can have different prescriptive outcomes depending on:
- the statute used,
- qualifying circumstances alleged, and
- the dates and forums of filing.
Defense and prosecution both litigate prescription aggressively. Prescription defenses often focus on:
- exact incident dates vs disclosure dates,
- whether concealment applies,
- whether the complaint filed at the prosecutor level interrupts prescription,
- whether dismissals and refilings restarted the clock.

13) Quick reference summary (most common RPC outcomes)

Rape by sexual assault (RPC):

Often 10 years (if correctional penalty applies in the charged form)
Can be 20 years (if qualified and penalty reaches reclusion temporal)

Acts of lasciviousness (RPC):

Often 10 years (correctional penalty)

Child-victim “lascivious conduct” charged under special law:

Frequently has longer periods depending on the statute and penalty; analysis must shift to the special law and/or Act No. 3326 rules.

14) Final takeaways

In the Philippines, prescription in sexual offense cases is penalty-driven: identify the exact charge and imposable penalty first.
The prescriptive clock starts either on commission or, in legally recognized circumstances, on discovery of a concealed offense.
Prescription is generally interrupted by the proper filing that commences the criminal process, but the details can be determinative.
For minors and special-law charging, prescription analysis often becomes statute-specific and fact-intensive, especially on discovery and concealment.