Witness Testimony

What is the rule for lay witness testimony?

A lay witness may only testify to opinions that: (1) are rationally based on the witness’s perception; (2) is helpful to the case; and (3) is not based on specialized knowledge/expert.

A witness is permitted to provide expert testimony if:

A witness may provide expert testimony if: (1) qualified as an expert by knowledge, skill, experience, training, or education; (2) the specialized knowledge is helpful to the case; (3) the testimony is based on sufficient facts or data; (4) the testimony is a product of reliable methods; (5) the expert has reliably applied the methods; and (6) the unfair prejudice does not substantially outweigh the probative value.

What are the bases for expert opinion?

Experts may base opinions on facts: (1) they personally observed; (2) information provided to the expert in court; or (3) information provided to expert out of court, even if inadmissible. An expert may rely on inadmissible evidence if other experts reasonably rely upon that type of information. As a general rule, expert may not disclose inadmissible evidence during trial unless the probative value substantially outweighs its prejudicial effect (reverse 403) .

What is the difference between expert and lay witness testimony?

personalized knowledge v. specialized knowledge