1) What “prescription” means in Philippine criminal law

Prescription of crimes is the running of a legally fixed period after which the State loses the power to prosecute an offense. It is a mode of extinguishing criminal liability under the Revised Penal Code (RPC). Once the crime has prescribed, courts should dismiss the criminal case (or refuse prosecution) even if the act actually happened.

Prescription is different from:

Double jeopardy (a constitutional bar after a valid prior case).
Provisional dismissal (a rules-based bar if the prosecution fails to revive a case within a set time).
Prescription of penalties (loss of power to enforce a sentence after conviction).

This topic focuses on prescription of the crime itself (the right to prosecute).

2) Where the rules come from

For offenses under the RPC (including most “physical injuries” offenses), the key provisions are:

Article 90 (prescription periods based on the penalty attached to the offense)
Article 91 (when prescription starts and how it is interrupted)
Articles 92–93 (prescription of penalties and related rules)

Procedural rules (Rules of Criminal Procedure) and doctrines in jurisprudence flesh out how filing and dismissals affect prescription.

3) What counts as “Slight Physical Injuries”

Under the RPC, Slight Physical Injuries is generally a less serious form of physical injury (commonly associated with very short incapacity/medical attendance, or minor injuries not falling under more serious categories). Its principal penalty is typically within arresto menor and/or fine, placing it in the category of light felonies/offenses for prescription purposes (classification depends primarily on the principal penalty prescribed by law for the offense).

Practical note: Many people casually label injuries as “slight,” but the legal classification can shift depending on the medical findings, days of incapacity/attendance, circumstances, and how the charge is framed. That matters because prescription depends on the penalty for the offense charged.

4) The prescriptive period for slight physical injuries

General rule under Article 90 (RPC)

The prescriptive period is determined by the penalty prescribed by law for the offense. Under Article 90, the shortest category is:

Light offenses prescribe in two (2) months.

Because slight physical injuries is generally punishable by arresto menor (a light penalty), it is commonly treated as a light offense for purposes of prescription, therefore prescribing in two (2) months.

What this means for a “20 years later” scenario

If the incident truly falls under Slight Physical Injuries under the RPC, then a criminal case cannot be initiated or revived after 20 years. It would have prescribed long, long ago—typically within two months, unless something legally interrupted the running of prescription.

So, as a baseline answer: No—after 20 years, a slight physical injury case cannot be “reopened” as a criminal prosecution, because it has almost certainly prescribed.

5) When prescription starts running (Article 91)

Default start date

Prescription generally starts to run from the day the crime is committed.

If the crime is not known immediately

If the offense is not known at the time of commission, prescription runs from the day of discovery and (in RPC framing) ties into the institution of proceedings. In practice, for physical injuries—especially where parties know each other and the injury is apparent—this “unknown crime” scenario rarely extends time meaningfully.

Continuing/complex scenarios

Some offenses have rules where the period runs from cessation (e.g., continuing crimes). Slight physical injuries is ordinarily not treated as a continuing offense.

6) What interrupts (stops) the running of prescription

Under Article 91, prescription is interrupted by the filing of the complaint or information and then it runs again in certain circumstances.

Key ideas:

A) Filing a complaint/information

The running of prescription is generally interrupted when a complaint (for purposes of initiating prosecution) or information is filed in a manner recognized by law and procedure.

Because slight physical injuries prescribes very quickly, timely filing is decisive.

B) What if proceedings end or stall?

Article 91 also contemplates that prescription continues to run again when:

Proceedings terminate without conviction or acquittal (e.g., dismissal not on the merits), or
Proceedings are unjustifiably stopped for reasons not attributable to the accused.

This prevents the State from “parking” a case indefinitely.

C) Barangay conciliation (Katarungang Pambarangay) and related pre-filing steps

Many minor disputes must pass through barangay conciliation before court filing. As a practical matter, these processes can affect timing, and certain laws/rules recognize that required pre-filing processes can suspend or affect prescriptive periods in limited ways.

However, even accounting for those effects, 20 years is far beyond any plausible suspension for a light offense.

7) “Reopening” after dismissal: how it interacts with prescription and other bars

People use “reopen” in different ways. Here are the main legal buckets:

Scenario 1: No case was ever filed within the prescriptive period

If the incident occurred and no complaint/information was filed in time, the crime prescribed.
After 20 years, prosecution is time-barred.

Scenario 2: A case was filed, then dismissed

Whether refiling is possible depends on why it was dismissed and what stage it reached:

A) Dismissal that triggers double jeopardy If jeopardy attached (valid complaint/information, competent court, accused arraigned, and a termination without the accused’s consent or otherwise qualifying), double jeopardy may bar refiling—even if prescription is not the issue.

B) Provisional dismissal A provisional dismissal can become permanent if the case is not revived within the rule-based time limits. For offenses punishable by imprisonment not exceeding six (6) years, the bar generally becomes permanent after one (1) year from issuance of the order of provisional dismissal (subject to rule conditions). Slight physical injuries falls on the low end, so a 20-year gap would be far beyond this window.

C) Dismissal without prejudice before jeopardy attaches Even if refiling is theoretically allowed, the prosecution must still beat prescription. With a light offense, that’s a very narrow window unless it was validly interrupted and remained tolled in a legally defensible way.

Scenario 3: There was a conviction, but years later enforcement is sought

That’s no longer “prescription of crimes,” but prescription of penalties (Articles 92–93). This matters only if there was a final conviction and the State is enforcing the sentence long afterward.

8) Does changing the law affect prescription? (e.g., penalty amendments)

When penalties are amended (for example, statutory adjustments to fines and related thresholds), lawyers examine:

the penalty prescribed at the time of commission, and
whether a later law is more favorable to the accused and can apply retroactively (a general principle in penal law when favorable and not a habitual delinquent situation).

Even under a favorable-change analysis, a two-month prescriptive period is already extremely short; and regardless, 20 years dwarfs the relevant timelines.

9) What about the civil side—can damages still be claimed after 20 years?

Criminal prescription does not automatically answer all possible civil remedies, because Philippine law recognizes different civil causes of action:

A) Civil liability “ex delicto” (arising from the crime)

Civil liability connected to the offense is commonly pursued with the criminal case. If the criminal action can no longer be brought, recovering civil damages as a consequence of the crime becomes difficult in practice and may be affected by prescription rules for civil actions.

B) Independent civil actions (often relevant: quasi-delict/tort)

A harmed party might consider civil actions based on quasi-delict or injury to rights, which have their own prescriptive periods under the Civil Code (commonly shorter than 20 years for personal injury-type claims).

Bottom line: Even if someone tries to pivot to a purely civil route, a 20-year delay is very likely time-barred for ordinary personal injury/damages theories, absent very unusual facts that legally suspend or interrupt civil prescription.

10) Practical takeaways for “20 years later” slight physical injury claims

Slight physical injuries under the RPC typically prescribe in two (2) months.
After 20 years, a criminal prosecution is effectively impossible due to prescription, unless there is an extraordinary, legally recognized interruption that somehow kept the prescriptive clock from running—something that is not realistically consistent with a 20-year gap for a light offense.
If “reopening” refers to a previously dismissed case, additional bars may apply, including double jeopardy or the rule on provisional dismissals, both of which also make a 20-year revival untenable.
Switching to a civil case after 20 years is also generally time-barred for personal injury-type claims, though the exact civil theory matters.

11) Common misconceptions

“There’s no prescription if the victim is willing to testify now.” Willingness to testify does not revive a prescribed criminal action.
“It can be reopened because it was reported to the police.” A police blotter/report is not automatically the same as a legally effective filing that interrupts prescription for all purposes. Timing and the proper prosecutorial steps matter.
“It’s a continuing wrong because the victim still feels pain.” Ongoing effects are not the same as a continuing crime. Physical injuries offenses are generally completed at the time of infliction.

This is general legal information in Philippine context, not a substitute for advice on specific facts (which can change classification, timelines, and applicable procedural bars).