Evidence — Overview

What are the principal types of evidence?

Real or physical evidence, testimonial evidence, documentary evidence, and demonstrative evidence.

What is real or physical evidence?

A tangible object presented to prove or disprove a fact, such as DNA, footprints, or a weapon.

What is testimonial evidence?

Evidence provided by a witness who testifies under oath.

What is documentary evidence?

Evidence contained in writings, recordings, photographs, or other documents.

What is demonstrative evidence?

Evidence used to illustrate, explain, or clarify other evidence.

What is the general rule of admissibility?

Relevant and reliable evidence is generally admissible unless excluded by a rule, statute, privilege, or public-policy consideration.

What two requirements make evidence relevant?

The evidence must be both material and probative.

What does it mean for evidence to be material?

It relates to a fact or legal issue that matters in the case.

What does it mean for evidence to be probative?

It tends to make a material fact more or less probable than it would be without the evidence.

What is the basic formula for relevance?

Material plus probative equals relevant.

Is all relevant evidence automatically admissible?

No. Relevant evidence may still be excluded by another evidentiary rule.

When may a judge exclude relevant evidence under Rule 403?

When its probative value is substantially outweighed by the danger of unfair prejudice, confusing the issues, misleading the jury, undue delay, wasting time, or needlessly presenting cumulative evidence.

What is unfair prejudice?

The danger that the jury will decide the case on an improper or emotional basis rather than on the evidence.

What is cumulative evidence?

Needlessly repetitive evidence that proves the same point as evidence already presented.

Why are some kinds of evidence excluded for public-policy reasons?

To encourage socially desirable conduct without fear that the conduct will later be used as evidence of liability.

Is an offer to pay another person’s medical expenses admissible to prove liability?

No. An offer to pay medical expenses is inadmissible to prove liability for the injury.

Why is an offer to pay medical expenses inadmissible to prove liability?

Because the law encourages people to help injured persons without fearing that the offer will be treated as an admission of fault.

What is character evidence?

Evidence concerning a person’s general disposition, reputation, or personality traits.

What is the general rule for character evidence?

Character evidence is generally inadmissible to prove that a person acted in accordance with that character on a particular occasion.

May the prosecution prove that a defendant committed theft merely by showing that the defendant has a reputation for dishonesty?

Generally, no. That would improperly use character evidence to prove conduct in conformity with character.

What does authentication require?

The offering party must provide sufficient evidence for a reasonable jury to find that the item is what the party claims it is.

How may physical evidence be authenticated?

Through witness testimony, a reliable chain of custody, distinctive characteristics, or other supporting evidence.

What is a chain of custody?

A documented sequence showing who possessed and handled an item of evidence from its collection until its presentation in court.

What is self-authenticating evidence?

Evidence that requires no extrinsic proof of authenticity to be admitted.

What are examples of self-authenticating documents?

Certain certified public records, official publications, and newspapers.

What does the best evidence rule require?

When a party seeks to prove the contents of a writing, recording, or photograph, the original is generally required.

Does the best evidence rule always require the original?

No. A duplicate or other secondary evidence may be admitted when an exception applies.

What is lay opinion testimony?

An opinion given by a non-expert witness.

When is lay opinion testimony admissible?

When it is rationally based on the witness’s perception and helpful to understanding the testimony or determining a fact in issue.

What are examples of permissible lay opinions?

Statements such as “He appeared angry” or “Her leg looked severely injured.”

What is expert opinion testimony?

An opinion concerning a scientific, technical, or specialized matter given by a qualified expert.

When may an expert give an opinion?

When the expert’s specialized knowledge will help the factfinder understand the evidence or determine a fact in issue.

What is impeachment?

An attack on a witness’s credibility.

What is the purpose of impeachment?

To help the factfinder evaluate whether the witness’s testimony should be believed.

What are common methods of impeachment?

Showing impaired perception or memory, bias, motive, prior inconsistent statements, certain criminal convictions, or a character for untruthfulness.

What is hearsay?

An out-of-court statement offered to prove the truth of the matter asserted.

What is the general rule for hearsay?

Hearsay is inadmissible unless an exclusion or exception applies.

Why is hearsay generally inadmissible?

Because the opposing party ordinarily cannot cross-examine the person who originally made the statement.

Is every out-of-court statement hearsay?

No. It is hearsay only when offered to prove the truth of what the statement asserts.

When is an out-of-court statement offered for its effect on the listener not hearsay?

When it is offered to explain the listener’s knowledge, belief, fear, notice, or subsequent conduct rather than to prove that the statement was true.

What is an example of a statement offered for its effect on the listener?

A warning that someone carries snakes may be admitted to explain why the listener became afraid and acted in self-defense, not to prove that the person actually carried snakes.

Why do hearsay exceptions exist?

Because some out-of-court statements are considered especially necessary, reliable, or trustworthy under the circumstances.

What is an evidentiary privilege?

A rule protecting certain confidential communications from compelled disclosure in court.

What are examples of testimonial privileges?

Attorney–client privilege and spousal communications privilege.

What does attorney–client privilege protect?

Confidential communications between an attorney and client made for the purpose of obtaining or providing legal advice.

Why does attorney–client privilege exist?

To encourage clients to communicate fully and honestly with their attorneys.

What does the spousal communications privilege protect?

Confidential communications made between spouses during the marriage.

What is the crime-fraud exception?

Attorney–client privilege does not protect communications made to obtain legal assistance in committing or furthering a crime or fraud.

Does attorney–client privilege protect a client who asks an attorney to help conceal an ongoing crime?

No. The crime-fraud exception applies.