Persuading A Jury


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  • Created by: Faye
  • Created on: 07-04-10 01:19

Effect of order on testimony

- Should council present their case as a story unfolding in chronological order?
-Should they use the benefit of the primary-recency effect to present their best witnesses first or last?
Would this disrupt the order of events in the jurors mind?

Murdoch(1962) in a labortary study using word lists discovered an effect know as the primacy effect. Where words at the beginning of a list were more likely to be recalled. This would suggest that the prosecution had an advantage, as this evidence is alwyas given first, however, later research by Glanzer & Cunitz (1966) discovered the primacy/recency effect. Where the participants recall words from the beginning and end of a list, but forget the middle . This would suggest that the mosy important pieces information are at the beginning of the trial (prosecution statement) and end (Judge's summing up)

In light of the above, careful consideration must be given to the order in which information is presented in court. Is it best to present information in strict story order(from the beginning to the end in chronological order of events) or should the best witnesses be presented first or last to take advantage of the primacy/recdency effect? Research by Pennington & Hastie (1988) shows that story order is best, any other order can be confusing for the jury.

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Pennington & Hastie (1988) Effects of memory struc

Aim- To investigate whether or not story order or evidence summaries are true causes of the final verdict and the extent to which story order effects confidence in those verdicts.

A labortarory experiment
The 2nd of two reported in this study

Participants- 130 students from northwestern univerisity and chicago university were paid to participate in an hour long experiment. They were allocated to one of four conditions.

The conditions:
39 prosecution items(Guilty) in story order
39 prosecution (Guilty) in witness order
39 defence items (Not Guilty) in story order
39 defence items(Not Guilty) in witness order

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Pennington & Hastie (1988) Effects of memory struc


-Participants listened to a tape recording of the stimulus trial (Massachusetts v Cadwell) and then responded to written questions
-Told to reach either a guilty or not guilty verdict on a murder charge.
- Asked to rate their confidence in thier own decision on a 5 point scale
-They were seperated by partitons and did not interact with each other
- In the story-order condtion, evidence was arrnaged in its natural order
- In the witness order condition, evidence items were arranged in the closest to the original trial
-The defence items were comprised of 39 not- guilty pieces of evidence and the prosecution items, 39 guilty pieces of evidence from the original case
-In all cases, the stimulus trial began with the indictment and followed the normal procedure, ending with the judges instructions.

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As predicted, the greatest confidence in their verdicts was expressed by those who heard the defence or prosecution in story order,
The lowest level was by the group who heard both witness order prosecution and defence.

-This shows that presenting the case in story order has persuasive effect.
In this sudy the effect in the defence case was much smaller.
- However, Pennington & Hastie argue that in the case they chase the defence case was much less plausible (The victim was drunk and lunged forwards onto the assailant's Knife)

2. Persuassion
Expery witnesses are widley used in criminal trials to add scientific credence to evidence. From research by Loftus Et al we know that eye witness testominy is notoriuosly unrealiable. Psychologists such as Loftus are often called as expert witness for the defence to warn jorors of the possible problems with eye witness testimony. However, reasearch has shown the jurors tend to disregard these warning and still believe eye witness accounts.

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Cuter et al- The effect of the expert witness on j

Aims: To investigate whether hearing about psychological research from an expert witness which casts doubt on the accuracy of eye witness testimony would affect a juror's decision-making by making them more sceptical.

Procedure: 538 undergraduates viewed a videotape mock trial of a robbery. Afterwards they individually completed a questionaire, containing the dependant measures which were verdict, a memory test and rating scales of how confident they were in their verdict. There were four independent variables

1. Witness Identifying Conditions (WIC). These were either good (no disguise, a hidden gun, a 2-day delay in identification and no suggestive instructions during the line- up) or bad( robber disguised. handgun, 14-day delay and suggestive instructions during line-up)

2.Witness confidence. Witness said they were either 100% or 80% confident that their identification was correct

3.Form of testimony. Expert witnesses either have gave a descriptibe testimony about EWT or relied on % and figures

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4. Expert opinion. The expert expressed an opinion on a scale of 0-25 on the accuracy of the testimony, this coincided with the good or bad WIC in variable

Jurors verdicts:
When WIC was good, more guilty verdicts were given and this effected increased if the expert witness gave a descriptive testimony.
Juror memory: 85% correctly recalled the testimony, so poor memory cannot be blamed.
Juror Confidence. This was good in the good WIC condition. It was stronger if the witness was 100% and increased if the expert witness also expressed confidence

Conclusion: This experiment shows that the expert testimony improved jurors knowledge and made them pay more attention to WIC. With expert testimony, Juror sensitivity to problems with evidence is improved and may help to prevent miscarriages of justice.

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Effect of evidence being ruled inadmissible

The law says that in order for evidence to be admissible in court. Its relevance most outweigh its potential for prejudice. Inadmissible evidence includes hearsay, past convictions and evidence obtained by illegal means. if inadmissible evidence is presented in error by a witness, the judge will direct the jury to disregard what they have just heard. However, by drawing their attention to it, it may be that the jury in fact pays even more attention to it. This is know as reluctance theory and suggests that jurors perceive instructions to ignore evidence as undermining their freedom to take all evidence into account.

Meaning of inadmissible: All evidence in the court should be admissible
There's an endless amount of inconsistency and several expectations, but one of the most important rules of evidence in a court is the hearsay rule. This rule prohibits secondhand testimony, or evidence of the "he said, she said" variety, during a trial. If an eye witnesses to an accident tells his friend the details after event, the eye witnesses friend's testimony would be hearsay and considered inadmissible.

The main reason for declaring inadmissibility is to make sure evidence is reliable and fair to both sides of a case.

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Pickel- Investigating the effect of instructions

- To look at the effect of prior convictions
- To look at the role of the judge's instructions when they were followed by a legal explanation.
-To examine how much the credibility of the witness affects the juror's ability to ignore inadmissible statements.

Participants: 236 Bali State University psychology students. They were assigned randomly to one of the conditions in an independent measures design.

Procedure: There were two conditions; both groups listened to an audio tape of a mock trial. Critical evidence was introduced 'accidenally' by a witness, this was objected to and the judge ruled that it was inadmissible and that the jury should ignore it. In one condition this was followed by a legal explanation of why the evidence was inadmissible, in the second condition this explanation was omitted. Participants were asked to decide on a verdict, the probable guilt of the defendant, a 10 point scale on the effect of knowledge of prior convictions and the credibility of the witness

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Results: Mock jurors who heard the evidence rules inadmissible, but received no legal explanation were able to ignore it and found the defendant guilty.

Those who heard the evidence rules inadmissible and were given a legal explanation were less likely to find the defendant guilty and had clearly not been able to ignore it.

The credibility of the witness and knowledge of prior convitions had no significant effect.

Conclusion: It would seem that calling attention to inadmissible evidence makes it more important to the jury and they pay it more attention.

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