Lay and expert opinions

Question 1

lay witness opinion

Answer 1

• rationally based on W’s perception (doesn’t need ot set forth facts opinion is based on)
• helpful to understand W’s testimony
• not based on expertise
• not speaking in legal terminology

Question 2

exert witness opinion

Answer 2

• qualified as expert thru knowledge, skill, experience, training, education
• knowledge will help jury to understand evidence or determine a fact in issue
• based on sufficient facts and data
• ———anything which is admissible in their field
• ———can be hearsay
• ———if inadmissible, may disclose only if probative value substantially outweighs prejudice
• product of reliable principles/methods: variety of factors to consider
• expert has reliably applies principles/methods to the case
• expertise cannot be in domestic law, memory, credibility

Question 3

opinion on ultimate issue

Answer 3

Allowed!

exception: expert opinion re: mental state or condition of D in a criminal case