EXPERT EVIDENCE / LAY OPINIONS

EXPERT OR LAY WITNESS?

*COMPARING facts of this case to other experiences => suggests EXPERT

Expert: Testimony based on some “scientific, technical, or other specialized knowledge.”

*Plus factor: if witness seems to be holding themselves out as an expert “given my yrs of exp…”

-“reasoning which can only be mastered by specialists in a field” (Committee). Jury would be unable to apply the same reasoning based on the facts. Not able to determine credibility.

-(some) any specialized experiences beyond the facts of this case => expert.

Ex: former narcotics gang taste-tester, expert on source of MJ. Expert.

Ex: Cops stating opinions based on experiences from past cases. Specialized knowledge => Expert.

But see Ayala: Not an expert (Mitch thinks he was) 1) on drug selling point, simple reasoning (but it was still specialized knowledge from prior experiences); 2) drug packaging (extreme outlier decision).

Lay witness: this opinion “results from a process of reasoning familiar to everyday life” (Committee).

Ex: 14 year old girl who had done cocaine ‘several times’ was lay witness re: whether the white powder she ate from a shoe was cocaine. Lay witness.

=>LAY OPINION

a) Based on lay witness’s own personal perceptions/knowledge

-Must lay a foundation for prior experiences that give knowledge.

b) Rationally based on the that perception

NOT ‘rank speculation’

-Creepy Farmer: statements about dead body are OK (“floopsy” and cold), but not opinion on how long he had been dead. Rank speculation unless he had previous expertise (then not lay W)

c) Lay opinion helpful to the fact finder?

HELPFUL: clarifies the witness’s testimony OR helps determine a disputed fact

Ex: clarifies when providing info through specific factual statements would be impractical, allowed to speak in plain language: “the defendant fired the gun by accident”

UNHELPFUL: making a specific credibility determination that jury can make for itself

-But see Melling (Kozy): Helpful (but Mitch disagrees) 911 operator opinion on Melling’s faked grief. But jury could hear tape for itself, and seems like he’s relying on specialized experience.

NO=>Inadmissible

YES=>Admissible, for ultimate issues in the case, when attempting to provide thru specific factual statements wouldn’t be helpful *403 issues if xpressed in same language as jury instructions.

=>EXPERT OPINION

0)*Court can appoint their own expert in addition to the parties’ - sua sponte or upon mtn [FRE 706]

1) Reasonable foundation for their opinion?

-Personal knowledge-Expert: in quality and origins of marijuana (US v. Johnson).

-Information the expert learned in preparation for testimony

-Training and education

-Inadmissible evidence can be relied upon…

IF experts in the field reasonably rely on those kinds of facts or data.

“reasonably rely”

-1st Cir: reasonably means usually. Based on frequency. (ex: ‘bizzare’ med record).

-MAJ: not based on frequency.

-Confrontation Clause: only implicated if expert wasn’t conducting her own independent analysis of the data provided by others. (Lewis).

*DX: counsel cannot bring the evidence up.

UNLESS (rev. 403) probative value (to help the jury understand) substantially outweighs risk of prejudice. Data needs to be disclosed in order for jury to appreciate the opinion.

CX: opposing party can inquire into these underlying facts and data. Including privileged information. So relying on privileged info works a waiver of the privilege.

2) Specialized knowledge will help the fact-finder understand the evidence or to determine a fact in issue;

*has to be an expert for the opinions offered for in other words.

-Counterexamples: matters of common knowledge; pure questions of law

*overlaps w/ standard to be an expert, helpful if its specialized reasoning jury couldn’t do.

3) Expert’s opinion is the product of reliable principles and methods?

Rationale: judge as gatekeeper bc juries aren’t capable of evaluating the expert(s). And some cutting edge science might be correct, but not widely accepted yet, and vice versa (shitty but accepted). Also, some sort of credibility check on whether the methods can be applied here. Frye left that to the jury.

-Fact that expert has already been admitted in other cases militates strongly for admission here.

*Non-scientific “specialized knowledge” experts (...

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