Testimony

Question 1

Opinion testimony from a lay W is only ok when it is

Answer 1

based on perception
helpful to the jury
and
not based on specialized knowledge

Question 2

scientist testifies that he personally tested the gold using reliable/ accepted methods, and in his opinion it is
the gold that was stolen.

admissible? why?

Answer 2

yes-

• scientific, technical, or other specialized knowledge
• based on sufficient facts
• product of reliable principles
• principles have been applied reliably

Question 3

Expert testifies that D suffers from schizophrenia, and was insane at the time that he stole yoga mats from target.

objecitonable?

Answer 3

yes- expert may testify as to what D had, but not state an opinion about whether the D did nor did not have a mental state or condition that constitutes an el of the crime or defense-

the trier of fact alone decides.

Question 4

scientist testifies that he personally tested the gold using reliable/ accepted methods, and in his opinion it is the gold that was stolen.

Does he have to testify to the underlying facts and data that he got from the test?

Answer 4

no, but may be required to give on xexam

Question 5

Expert testifies that in his opinion, the D breached his duty of care to P in a medmal case.

Admissible under CL/ FRE?

Answer 5

CL: no opinions on ultimate issues allowed

FRE: ok
the only thing that isnt is testimony as to the mental state of D in a crim case

Question 6

L wants to xexam expert using a treatise that says the opposite of expert’s opinion.

Is he allowed to use it under FRE/ CL?

Answer 6

CL: no, unless it was referred to or relied on at trial (ok for impeachment) , or expert wrote it, or the writing is in ev.

FRE: ok to xexam experts on statements contained in any published treatise of reliable authority. Can be admitted substantively and for impeachment