Expert & Lay Witness Testimony Flashcards
FRE 701 lay witness opinion
a. Personal knowledge
b. Things you can perceive
c. Cannot draw upon specialized knowledge (Can’t have an expert in lay witness clothing)
FRE 702 Expert Witnesses
a. Do not need personal knowledge but can have it
b. Can offer inference and conclusions
c. Can educate jury about how world works (i.e. trouble identifying strangers cross racially)
d. Can generate their own facts (i.e. chemists)
Williams v. Illinois: Expert Testimony is Not Hearsay
Not being admitted for the truth of the matter asserted, simply explaining the assumption made from the reports
FRE 706 Court Appointed Experts
a. Court can appoint its own expert witness, also defines expert’s role
b. American judges don’t like this because this is the European style fact finding role
c. Rarely used
Fyre Test (Bad Law)
The scientific method being used by the expert must be generally acceptance by the field of which it belongs
Daubert: Rejection of Fyre
No longer using Frye, use FRE to determine
Trial judge is required (consistent with 104) to determine if expert testimony is admissible.
Polygraph Admissibility
US v. Scheffer: No constitutional violation for a ban on evidence of polygraphs; No consensus in the scientific community on the reliability of these tests
Many jdxs ban polygraph from coming in, some allow, lots use it as a negotiating tool even knowing that the evidence can’t come in IN OTHER WORDS DON’T CONSENT TO POLYGRAPHS
DNA Evidence Admissibility
a. Just trust me I’m an expert does not cut it
b. Must explain the methodology behind it
c. United States v. Davis: An expert witness’s source-attribution statement is admissible if it indicates that a defendant is the source of DNA evidence to a reasonable degree of scientific certainty.
