Juries and decision making

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Juries and decision making
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Trial by jury

• Only 2 of criminal cases put before jury in
  England and Wales
• Inquisitorial system vs. adversarial system
• Lay person jury vs. escabinato jury

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Overview

• Factors affecting jury decisions
• Jury size
• Jury decision rules
• Bias?
• Possible improvements to aid jurors

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Hung juries(Arce et al. 1998)

• Deliberated longer
• Members employed more assertions when
  communicating with other members of jury
• More simultaneous interruptions
• Tended to use less trial evidence

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Real jury deliberationMyers (1979)

• Approx 700 cases in Indiana tried by jury
• Obtained qualitative data from
• File folders of assistant prosecutor
• Police arrest records
• Telephone interviews
• Informal discussions with prosecutors and court
  personnel

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Factors influencing jurys decision of
guiltMyers (1979)

• Weapon recovered
• Large number of witnesses specified
• Defendant had previous convictions
• Defendant unemployed
• Age of victim
• Less serious crime

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Jury sizeSaks Marti (1997) Arce et al. (1998)

• Larger juries deliberate longer
• Hung verdicts more common for larger juries
• Mock juries
• Guilty verdicts no more common in larger juries
• Smaller juries refer less to evidence
• Smaller juries fewer pro-defendant arguments
• Civil cases
• Smaller juries tend to award more to injured
  party

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Jury decision rules

• Unanimous vs. majority decision
• Unanimous decision rule
• More reference to evidence
• Link evidence to legal issues
• Examine evidence in more detail
• Deliberations more exhaustive and detailed
• Majority decision rule
• More driven to reach verdict
• More likely to begin deliberations with a vote

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Does pre-trial publicity affect jury?

• Some jurisdictions limit media coverage once
  suspect charged
• Only affects small number of cases

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Effects of pre-trial publicity Studebaker et
al. (2000)

• Oklahoma City bombing
• Analysed newspapers in Oklahoma City and Denver
• Oklahoma newspapers more negative pre-trial
  publicity
• Surveys indicated Oklahoma residents more
  confident of McVeighs guilt.

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Jury selection

• Voir dire
• Peremptory challenge
• Issue in US
• Abolished in England Wales in 1988
• Assessing potential bias in juries
• scientific jury selection
• Assess possible prejudices in mock jury panel

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Jury selectionZeisel Diamond (1978)

• Compared potential jurors who had been challenged
  as biased with actual jurors
• No difference between verdicts of actual and
  biased juries

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Possible aids to jurors

• Note-taking
• May be helpful (but evidence not striking)
• Question-asking
• No negative consequences
• May benefit

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Useful references

• Arce, R., Farina, F., Novo, M. Seijo, D.
  (1998). In search of causes of hung juries.
  Expert Evidence, 6, 1-18.
• Saks, M. Marti, M. (1997). A meta-analysis of
  the effect of jury size. Law and Human Behavior,
  21, 451-467.
• Studebaker, C. A., Robbennolt, J. K.
  Pathak-Sharma, M. K., Penrod, S. D. (2000).
  Assessing pre-trial publicity effects
  Integrating content analytic results. Law and
  Human Behavior, 24, 317-336.