opinion testimony

Question 1

Lay Witnesses

Answer 1

admissible if (1) rationally absed on W’s perception, (2) helpful to jury, (3) not based on scientific or other speicalized knowledge

but note: cannot give opinions that require legal conclusions

Question 2

Expert Witness Requirements

Answer 2

1. expert is qualified
2. expert is reasonably certina
3. helpful to jury/trier of fact
4. based on sfuficient facts or data
5. based on reliable principles and methods
6. reliably applied (those principles and methods to the facts of teh case)

Question 3

Expert is qualified

Answer 3

Specialized knowledge, skill, experience, training, or education
* must match area they are offering an opinion in

Question 4

expert is reasonably certain

Answer 4

Reasonable level of certainty in correctness of opinion

cannot be a guess or speculation

Question 5

expert testimony is helpful to jury

Answer 5

Subject matter must be one where specialized knowledge would be helpful to jury; not just an inference anyonce could arrive at on their own

Question 6

expert testimony is based on sufficient facts or data

Answer 6

proper factual bases:
1. facts based on expert’s own personal observations
2. facts presented into evidence at the trial and made known to the expert
3. facts not in evidence that were supplied to the expert out of court and which are of a type reasonably relied upon by other experts in field in forming opinions on the subject (R 703)
* even if evidence is not admissible in this case (e.g. hearsay) can still be relied upon by expert but they cannot dislocse them unless court determines probative value outweighs prejudicial effect

Question 7

ET based on reliable principles and methods

Answer 7

Daubert Factors (used to decide if scientific methods are reliable)
* testing
* peer review and publication
* error rate within proper limits
* standards controlling operation
* general acceptance by other experts in the field

multi-factored: can weigh against each other

Question 8

Learned Treatises

Answer 8

admissible as substantive evidence during expert tesitmony

established as reliable authority
called to expert attention on cross or relied upon direct
except read into evdience

Question 9

opinion on ultimate issues

Answer 9

permitted unde R 704: “An opinion is not objectionable just because it embraces an ultimate issue.”

BUT in criminal case in which th D’s mental state constitutes an element of the crime, an expert may not state an opinion as to whether the accused did or did not have the mental state in issue