MBE Rules · Evidence

Lay opinion

FRE 701

The rule

A lay witness may give opinion testimony if (a) rationally based on witness's perception, (b) helpful to clearly understanding testimony or determining a fact, AND (c) not based on scientific/technical/specialized knowledge. Permissible: speed, intoxication, identity, emotional state, value of own property.

In plain English

A regular person can give their opinion in court if it's based on what they've directly seen or experienced, helps clarify things, and doesn't rely on expert knowledge.

Worked example

A neighbor testifies that the defendant seemed drunk because they saw them stumbling and slurring words. This is allowed because it's based on personal observation and helps show the defendant's condition.

Memory hook

Lay opinions: plain talk, no science. Witnesses can share what they see, not what they study.

The trap

Students think: any opinion is okay if relevant. Wrong, because it must be based on perception, not expert knowledge. The actual test is: perception, helpfulness, no specialized knowledge.

How examiners test it

The MBE loves: witness testifies about speed or sobriety. Trap: students assume any opinion is fine. Test if it's based on personal perception, not expertise.

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