Federal Rules of Evidence: Plain English Guide

Every rule explained simply — with examples, edge cases, and key exceptions.

Browse Rules by Category

FRE 401

Test for Relevant Evidence

Evidence is relevant if it makes a fact more or less probable and that fact matters to the case.

FRE 402

General Admissibility of Relevant Evidence

Relevant evidence is generally admissible; irrelevant evidence is not.

FRE 403

Excluding Relevant Evidence

A court may exclude relevant evidence if its probative value is substantially outweighed by the danger of unfair prejudice.

Key Concepts

Relevance

Evidence must be relevant — it must make a fact more or less probable. The court may still exclude relevant evidence if its prejudicial value outweighs its probative value.

Hearsay

An out-of-court statement offered to prove the truth of the matter asserted. Generally inadmissible, with 23 exceptions in FRE 803 and additional exceptions in FRE 804.

Authentication

Before evidence can be admitted, it must be authenticated — shown to be what the proponent claims it is. Digital evidence has specific authentication challenges.

Best Evidence Rule

To prove the content of a writing, recording, or photograph, the original must be produced unless an exception applies (FRE 1001-1008).

Digital Evidence Authentication

1
Preserve the Original
Create a forensic copy of digital evidence. Never work from the original file — any modification breaks the chain of custody.
2
Document the Chain
Record every person who handled the evidence and when. A break in the chain of custody can lead to evidence being excluded.
3
Use Hash Verification
Generate cryptographic hash values (MD5 or SHA-256) to prove the file has not been altered since collection.

Official Resources

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