Past Facts: Witnesses

Question 1

Eyewitness ID

Answer 1

a. Acquisition phase
i. Event factors
ii. Witness factors

b. Retention phase
i. Forgetting curve
ii. Post event info

c. Retrieval phase
i. Retrieval environment
1) i.e. lineup

d. Loftus & Palmer experiment
i. Use of wording to affect estimated speed of crash
1) i.e. “contacted” = 35 mph; “smashed” = 50 mph (same crash)
2) How likely to see broken glass?
Contacted = unlikely; smashed = very likely

Question 2

Chapple case

Answer 2

a. Uses Amaral/Dyas test
1) Testimony must be beyond the ken of average layperson (juror)
2) Expert witness must be qualified to give testimony

3) Methodology
a) Frye= methodology: generally accepted (Amaral)
b) Daubert= methodology: scientifically valid

   c) Probative value must outweigh prejudicial impact

Question 3

Chapple: Probative v. prejudicial?

Answer 3

a) Defense called well-known Dr. Loftus (witness ID expert)
i) Prosecution moves to block testimony
One. Too prejudicial as Loftus is too well known and highly regarded (jurors will just assume she is right)
Two. Doesn’t present evidence that is “beyond the ken”

b) Some prejudicial but probative value outweighs (Loftus so well regarded, could tip jury; but court says we need actual experts)
c) Loftus brings testimony that is “beyond the ken” of the average juror; therefore testimony OK

Question 4

Papailiou, Yokum, Robertson experiment

Answer 4

a. FL v. NJ standards
i. NJ reduced juror reliance on weak ID evidence
ii. But also decreased reliance on Strong ID evidence!
iii. Led to juries more likely to exonerate guilty D

Question 5

Henderson

Answer 5

a. Variables
i. System variables
1) Factors like lineup within control of criminal justice system
ii. Estimator variables
1) Factors related witness, crime scene, etc. over which criminal justice system has no control

iii. D has initial burden to show some evidence that there was an issue of system variable
1) Estimator variables don’t work alone, as usually all witnesses are under some sort of stress; must first show system variable

iv. To trigger pretrial hearing, court considers system variables
v. At Pretrial hearing, court considers system variables and estimator variables
vii. Leads to enhanced jury instructions which negates need for most expert witnesses

Question 6

Henderson Test

Answer 6

a) must allow the court to explore and weigh all relevant system and estimator variables at a pretrial hearing when there is evidence of suggestiveness
b) cannot be heavily weighted by factors that can be corrupted by suggestiveness
c) must meaningfully promote deterrence
d) must help jurors understand and evaluate the effects that various factors have on memory
e) must be flexible enough to guarantee fair trials to defendants and protect the state’s interest in presenting critical evidence at trial.