(A practical, everything-you-need-to-know guide in the Philippine context, updated for the Revised Rules on Evidence)

Core idea. Evidence is admissible if it is relevant to the fact in issue and not excluded by the Constitution, statute, or the Rules of Court. Everything else flows from this.

I. What counts as “evidence”

Object (real) evidence – tangible things perceived by the senses (e.g., weapons, drugs, clothing).
Documentary evidence – writings, recordings, photographs, electronic documents (including emails, chats, spreadsheets, body-cam footage, CCTV, phone screenshots).
Testimonial evidence – what a witness says under oath, based on personal knowledge or qualified opinion.

Tip: Photos, videos, audio files, and screenshots are treated as documentary, not object, evidence; they must be authenticated like other documents.

II. The two universal gates: Relevance and Competence

Relevance & Materiality – The evidence must logically relate to a fact of consequence in the case.
Competence (legal admissibility) – Even relevant proof can be barred by an exclusionary rule (e.g., hearsay, illegal search, privileged communication).

III. Constitutional exclusionary rules (automatic suppression)

Unreasonable searches and seizures – Evidence obtained in violation of Art. III, Sec. 2 is inadmissible, including “fruit of the poisonous tree.”
Custodial investigation – Extrajudicial confessions are inadmissible unless the accused is informed of rights and assisted by competent and independent counsel (Art. III, Sec. 12).
Privacy of communication – Evidence obtained through unlawful interception is excluded (Art. III, Sec. 3).
Due process / voluntariness – Coerced admissions or confessions are out.

IV. Burdens, standards, and presumptions (why admissibility matters)

Criminal: guilt beyond reasonable doubt; burden on the prosecution; accused benefits from presumption of innocence.
Civil: preponderance of evidence.
Administrative: substantial evidence (that a reasonable mind might accept).
Presumptions:
- Conclusive (irrebuttable) – e.g., estoppel by deed.
- Disputable (rebuttable) – e.g., official duty regularly performed; ordinary course of business; legitimacy/regularity of acts; mail duly sent is received; human experience in traffic of facts.

V. Testimonial evidence

A. Who may testify

All persons who can perceive and can make their perceptions known may be witnesses, except those disqualified by privilege or specific rules.
The old Dead Man’s Statute is gone under the Revised Rules; parties may now testify on transactions with a deceased or insane person (credibility is for the court).

B. Personal knowledge & oath

A lay witness may testify only to facts personally perceived. Speculation is excluded.

C. Opinion rule (and its exceptions)

General rule: Opinions are inadmissible.
Lay opinion allowed on identity, handwriting, emotional state, speed, or other rationally based perceptions helpful to the court.
Expert opinion allowed if the witness is qualified by knowledge, skill, experience, training, or education, and the opinion rests on reliable principles properly applied to sufficient facts/data. Courts act as gatekeepers.

D. Impeachment and rehabilitation

Impeachment by: prior inconsistent statements, bad reputation for truth, bias/interest, conviction of crimes involving moral turpitude, or specific defects in perception or memory.
Rehabilitation by prior consistent statements (to rebut recent fabrication), evidence of good reputation for truth, or explanation of inconsistencies.

VI. Hearsay and its key exceptions

A. Hearsay rule

Hearsay = an out-of-court statement offered to prove the truth of the matter asserted. It is generally inadmissible because the declarant isn’t under oath, observed by the judge, or cross-examined.

B. Statements that are not hearsay

Independent relevant statements (offered to prove that words were said, not that they’re true)—e.g., notice, demand, threats.
Admissions by a party (including authorized, adoptive, and vicarious admissions).
Prior testimony where all Rule requirements are met (e.g., same parties and opportunity to cross).

C. Traditional hearsay exceptions (high-value list)

Dying declarations (homicide-related cases; declarant believed death imminent; statement concerns cause/circumstances of death).
Statement against interest (declarant unavailable; the statement so far against declarant’s pecuniary/proprietary/penal interest that a reasonable person wouldn’t have made it unless true).
Declarations about pedigree and family reputation on pedigree.
Common reputation as to facts of public or general interest more than 30 years old, boundaries/customs, or matters of general history.
Entries in the course of business made at or near the time by a person with knowledge and kept in regular practice.
Entries in official records made by a public officer in performance of duty.
Commercial lists and compilations generally relied upon.
Learned treatises (to support expert testimony, if established as a reliable authority).
Contemporaneous statements/exclamations that elucidate a startling occurrence or accompany an equivocal act (often called “verbal acts” or res gestae aspects under the Revised Rules).
Residual exception (when recognized by courts)—trustworthy, necessary, and notice given to the adverse party.

VII. Documentary evidence

A. The Original Document Rule (Best Evidence Rule)

To prove the contents of a writing/recording/photograph, the original is required, except when:
1. the original is lost/destroyed without bad faith;
2. it’s in adverse party’s custody and they fail to produce after reasonable notice;
3. it’s a voluminous compilation (summary allowed with access to the source);
4. it’s a public record (certified copy suffices).

B. Authentication

Private documents must be authenticated by a witness with knowledge, by proof of handwriting, or other evidence of due execution.
Public documents (official acts/entries; notarized instruments; public records) are self-authenticating, subject to proof of due execution/issuance where necessary.
Foreign public documents require proper foreign certification; the Philippines’ accession to the Apostille Convention allows apostilled documents to be used without consular legalization, subject to court evaluation.

C. Electronic documents & signatures

Legal recognition: Electronic data messages and electronic documents are functional equivalents of paper writings.
Admissibility hinges on relevance and authenticity; evidentiary weight depends on reliability of generation, storage, and communication; integrity of the system; and method of identification.
Authentication may be by: digital signatures; security procedures; testimony of a person with knowledge of how the record was created/kept; hash values; metadata; or system descriptions.
Electronic signatures are attributable if a method identifies the signer and indicates approval.
Printouts of electronic data are admissible if shown to reflect the data accurately.

VIII. Object (real) evidence

Must be relevant, identified, and shown to be in substantially the same condition when examined by the court.
Identification can be by testimony (recognition/unique marks) or by chain of custody, especially for fungible/seizable items (e.g., narcotics).
Chain of custody calls for documenting each link—from seizure, marking, storage, transfer, to presentation in court—to eliminate reasonable doubt about substitution, tampering, or contamination.

IX. Exclusionary policies and “inadmissible even if relevant”

Subsequent remedial measures – not admissible to prove negligence/culpable conduct; may be used to show ownership, control, feasibility, or impeachment.
Offers to compromise
- Civil: generally inadmissible to prove liability; admissions of independently relevant facts made in the course of settlement talks may be received.
- Criminal: an offer to compromise by the accused may be taken as an implied admission of guilt, except in quasi-offenses (criminal negligence) and crimes allowed by law to be compromised.
Payment of medical expenses – not admissible to prove liability.
Pleas and plea discussions – withdrawn guilty pleas and related statements are inadmissible against the accused.
Subsequent remedial repairs, liability insurance, and character evidence limits (see below).

X. Character evidence

Criminal cases:
- The prosecution cannot prove the accused’s bad character to show propensity.
- The accused may introduce pertinent good character; if he does, the prosecution may rebut.
- Victim’s character may be shown when relevant (e.g., in self-defense on aggressor identity), subject to rape shield and other protections.
Civil cases: Character generally not admissible, except when character itself is in issue (e.g., child custody, libel truth defense).

XI. The Parol Evidence Rule

When a written agreement is the subject of the action and its terms are in issue, extrinsic evidence cannot vary the writing unless a party puts in issue, in the pleadings:

Intrinsic ambiguity, mistake, or imperfection;
Failure of the writing to express the true intent of the parties;
Validity of the written agreement (e.g., fraud, duress, illegality); or
Subsequent agreements modifying the written terms. If admitted, parol evidence is limited to the particular exception raised.

XII. Judicial notice and judicial admissions

Judicial notice (no evidence required) for:
- Matters of public knowledge;
- Facts capable of unquestionable demonstration;
- Matters the court is required to know (laws, official acts). Courts may take notice motu proprio or on request; parties should be heard when appropriate.
Judicial admissions (e.g., in pleadings or formal stipulations) are conclusive upon the party making them, unless shown to have been made through palpable mistake or no longer true due to supervening events.

XIII. Offers, objections, and preservation of error

Offer of evidence: done at the time the evidence is presented (oral testimony is “offered” by specifying the purpose; documents/objects are marked and offered when the witness who can identify them is on the stand).
Objections: state specific grounds; otherwise, defects may be deemed waived.
Motion to strike: used for answers given before objection or when answers exceed the question.
Tender of excluded evidence (offer of proof):
- Document/object: attach/mark for the record.
- Testimony: put on the record the substance of the expected testimony (questions and answers) so an appellate court can review the exclusion.

XIV. Secondary evidence playbook (when the original is unavailable)

To prove contents of a writing when the original is lost/destroyed without bad faith:

Prove loss or unavailability (search diligence, circumstances of loss).
Prove due execution/existence (e.g., subscribing witness, admissions, or business practice).
Prove contents (by copy, drafter’s testimony, or other reliable sources). Failure at any step is fatal.

XV. Special topics you’ll actually face in practice

Subpoena compliance: when originals are with a non-party custodian, subpoena duces tecum + reasonable time to produce; a certified true copy of a public record is usually enough.
Translations: foreign-language documents require competent translation; the translator may need to testify or certify.
Forensic and digital evidence: demonstrate system integrity (device, software, process), maintain hash values, and document chain of custody for seized gadgets and extracted data.
CCTV/body-cam: authenticate by operator/custodian or a competent witness; show the equipment was working, the process was reliable, and the recording is the same (no material alteration).
Scientific tests: establish valid methodology, proper calibration, qualified analyst, and unbroken specimen chain.
Admissions via social media and messaging apps: authenticate by linking the account to the person (subscriber info, device possession, prior communications, admissions) and showing the message’s integrity (metadata, export logs, screenshots with context).

XVI. Characteristic pitfalls (and how to avoid them)

Skipping authentication of private writings and screenshots.
Assuming “relevance = admissibility.” Always check exclusionary rules.
Hearsay inside hearsay. Each layer must fall under an exception.
Breaking the chain. For fungible or digital items, gaps create reasonable doubt.
Parol-evidence traps: if you didn’t plead an exception, your extrinsic proof won’t be heard.
Global objections (“Objection, your honor, hearsay”) without specificity. Preserve exact grounds.
Confessions without counsel. They will be suppressed, and may taint derivative evidence.

XVII. Quick checklists

A. Admissibility quick-scan

Is it relevant?
Is it barred? (constitution, statute, privilege, hearsay/opinion/character rules)
Is it properly authenticated? (who will identify it?)
Does a foundation/precondition apply? (original document rule, chain, expert reliability)
Have you pled any needed exception? (parol evidence)
Have you prepared your offer and objections? (and an offer of proof if excluded)

B. Authenticating common items

Private contract: signatory or subscribing witness; proof of handwriting; admissions.
Email/chat: account linkage + system/use testimony + metadata/hash if challenged.
CCTV/video: operator/custodian + working condition + unaltered copy + date/time basis.
Notarized deed: present notarized copy; it is a public document (subject to rebuttal).
Foreign public doc: apostille (or proper consular/authentication if from a non-apostille country).
Business records: custodian or qualified witness + regular practice + near-time entry.

XVIII. Remedies if your evidence is excluded (or opponent’s is admitted)

Make a clear offer of proof to preserve the issue for appeal.
Move to strike inadmissible testimony that slipped in.
Ask for a limiting instruction when evidence is admissible for one purpose but not another.
Object to cumulative or prejudicial evidence even if relevant (Rule 403-type balancing under court discretion).

XIX. Bottom line

Admissibility in Philippine courts is a disciplined four-step exercise: (1) ensure constitutional compliance; (2) clear the Rules (hearsay/opinion/character/parol/best-evidence); (3) authenticate and lay foundation (including chains, systems, and methods); and (4) preserve the record with precise offers and objections. Do that consistently, and you maximize what the court may consider—which is the entire point of evidence law.

This article is for general information and bar/practice review. For case strategy, apply the rules to your specific facts and forum orders.