Trial Procedures and Persuasion Techniques


According to the British Crime Survey for 2000 (Home Office, 2001b), a third of British adults had been to court as a witness, spectator or juror at some time. Ten per cent of the population had been to court accused of a crime. About two-thirds of British people believe that the criminal justice system respects the rights of and treats fairly people accused of committing a crime. The figure is slightly lower for those who have been in trouble with the law but, nevertheless, even they remained as a group very satisfied with the criminal justice system. There was less belief that the criminal justice system brings people who commit crime to justice. Only about 40% agreed with this. There was only a low level of agreement (approximately one in five) with the statement that the criminal justice system meets the needs of victims.

There is an obvious need to understand better what happens in courts of law. However, one must be realistic about the direct impact of courts on much crime. In the majority of cases, questions of guilt have been already settled by the admission of the accused. Williams (1995) points out that in some jurisdictions something like 90% of cases are settled by a plea of guilty. Of course, in the United States, this may involve plea bargaining - that is, prosecution and defense agreeing a guilty plea to a less serious charge than the prosecution originally intended (Colvin, 1993). This encourages more guilty pleas.




A. Fitness to Plead.

The insanity defence has been the subject of a tremendous amount of academic writing (and so will not be dealt with here), despite the fact that it is pleaded in only about 2% of cases and is rarely successful. The insanity defence, however, revolves around the mental state of the accused at the time of the crime. Of relevance to perhaps more defendants is the similar issue of the accused’s mental condition at the time of the trial. Whereas the insanity defence is of direct concern to defendants likely to be found guilty, competency to stand trial is important in that it may be an issue that prevents a genuinely innocent person standing trial for the crime for which he or she is accused. The innocent person accused of a crime may be at a severe disadvantage if, during the trial, he or she is confused, delusional or hallucinational; and secondly, such a person would be even more disadvantaged if he or she were to be incarcerated until such time as her mental condition is judged to be ‘normal’ once again. Furthermore, in the case of defendants with mental handicap, it is not an option for the court to await a recovery.

In the United States, for every one defendant acquitted by the insanity defence, approximately forty-five are remanded in prison hospitals after being judged incompetent to stand trial. The common law principal underlying this issue is that a person cannot be brought to trial in absentia. Although the person may be physically present, he or she may be deemed mentally ‘absent’ if there is reason to believe that he or she is unable to understand the proceedings being brought against them, or unable to adequately assist in their own defence. In most jurisdictions, such a trial is routinely delayed and the individual is incarcerated in a prison hospital in the hope that he or she may ‘recover’. However, with most psychiatric illnesses symptomised by hallucinations or delusions, such a recovery is unlikely to occur. Other severe consequences then face the individual. Bail is automatically denied. The accused is kept in a facility for the criminally insane and may well lose his or her job and undergo the trauma of separation from friends and family. It is not unreasonable to expect the mental condition of such individuals to deteriorate rather than to improve.

The case of Jones v. United States provides a startling illustration of the predicament of individuals being held in prison hospitals awaiting recovery. In 1975, Michael Jones was arrested for attempting to steal a jacket from a department store in Washington, D.C. However, upon medical examination, Jones was found to be suffering from paranoid schizophrenia. Although found competent to stand trial, and found not guilty by reason of insanity, Jones was committed to St. Elizabeth’s Hospital, Washington, to be held there until he ‘recovered’. Despite several hearings in the District of Columbia Court of Appeal and the US Supreme Court, Jones is still in hospital today, some 21 years later. The original charge was one of petty larceny, a misdemeanour punishable by a maximum sentence of one year’s imprisonment. The decision to find Jones competent to stand trial was surprising, given that paranoid schizophrenia is—by definition—symptomised by delusions of paranoia and a lack of insight into reality. However, even if he had been found incompetent, policy dictates that he would still have been committed to a prison hospital to await recovery and so would still be in such a facility today. Of more concern is that this would also be true even if Jones were originally falsely accused.

The expertise of clinical psychologists has had a considerable bearing on the issues surrounding competency to stand trial. In a 1972 US Supreme Court case, Jackson v. Indiana, a deaf-mute man with mental handicap, who was deemed incompetent to stand trial, was also deemed unlikely ever to become competent. Based in part on testimony from medical professionals, the Court ruled that if the defendant was unlikely ever to become competent, then the State should immediately institute civil commitment proceedings or release the defendant. Thus, the duration of pre-trial confinement should be no longer than the time taken to determine whether the defendant is incurably incompetent. This ruling represents a compromise between the rights of due process and those of a speedy trial and illustrates the importance of psychological knowledge in deciding when to legislate to compromise such rights.

Pharmacological therapies for psychiatric conditions have also lead to the introduction of ‘synthetic sanity’. If a drug can temporarily produce some rationality in an otherwise deranged defendant, then the trial may proceed. However, there are three main problems with synthetic insanity. Firstly, such therapies are by their nature temporary; severe side-effects can occur with prolonged usage. Secondly, if the insanity defence is pleaded, the apparent (but temporary) rationality of the defendant may lead a jury to reject the plea. And finally, the drugs in question have no effect on mental handicap, which is probably the most common condition of defendants whose competency is under question. In summary, the issue of competency to stand trial is still awaiting satisfactory resolution, on both a psychological and legal level. However, the role of the psychologist in proffering expert opinion on competency cannot be overstated. Furthermore, it is imperative that legal and mental health professionals work together in making a competency determination, given that a knowledgeable lawyer understands what is required from the defendant and a knowledgeable psychologist understands what is to be expected from the defendant.

The trial

The whole of the trial is a social situation with for­mal and informal interactions involved (see Table 1, below). This means that there are many psy­chological processes at work at each stage, other than the legal aspects of the trial.


Table.1: Stages in the trial process


Defendant’s plea

Prosecution opening statement

Defence opening statement


Defence closing arguments

Prosecution closing arguments

Judge’s instructions on procedures

Jury decision

Judge sentencing (if accused found guilty)


The jury decision can be influenced by three main aspects of the trial: pre-trial and trial influences and procedures, perception of the evidence and wit­nesses, and the work of the prosecution and defence lawyers.


Pre-trial influences

The most important extra-evidential influence is pre-trial publicity (PTP). This can be divided into two types: factual (including details of past criminal record of the defendant), and emotive (assuming guilt before the trial). Both types affect the juror’s view of the evidence. In fact, Timothy McVeigh (known as the Oklahoma Bomber) appealed in 1997 against his death sentence on the grounds of ‘emotive’ PTP.

In high-profile cases, it is almost impossible for the jurors to have not seen the PTP. Using newspa­per cuttings with a mock jury, Linz and Penrod (1992) found that PTP, including prior convictions and ‘sensational’ reporting, impacted on the jury decision. There is a legal question of whether jurors should know about the prior convictions of the defendant.

Padawer-Singer and Barton (1974) found 50% more ‘guilty’ decisions by jurors aware of a past criminal record and a retracted confession of the defendant, compared to not knowing this informa­tion. The judge’s instruction to ignore this has lit­tle effect.


Perception of the witness

The most important part of the trial is the evidence provided by witnesses. The accuracy of the evidence provided by witnesses is discussed elsewhere, but what is the impact on the jury of the witnesses’ evidence? In one of her experiments with mock juries, Loftus (1974) showed that wit­ness evidence is very powerful in the mind of the jury, and is only slightly diminished by discrediting the witness.  Some 150 mock jurors heard about a robbery and murder at a local store.  The three conditions were: a witness who saw a man leave the store, no witness and a witness with poor eyesight.  Where there was a witness the conviction rate was high, even if the witness had poor eyesight (72% for good eyesight and 68% for poor eyesight, compared with 18% for no witness).  This is also evidence of the perseverance effect — the tendency to believe the first thing people are told, even if it is later contradicted.

As well as the faith placed in witnesses by juries, there are also the general principles of impression formation of witnesses. For example, when wit­nesses are perceived as likeable, they are seen as more credible, whether working for the defence or the prosecution. Garcia and Griffit (1978) varied the likeability of the witnesses in a mock crime about a car accident

Likeability of Prosecution

Likeability of Defence

Mean rating of guilt














Another factor in the impression of witnesses is the language they use. Lakoff (1975) has high­lighted what could be called ‘powerless language’. This would include a high frequency of ‘hedges’ (for example, ‘I think’ and ‘perhaps’), and answering direct questions in an unsure way (for example, with rising intonation at the end of the sentence). Witnesses of either gender using this type of lan­guage were perceived as less intelligent, less compe­tent, less likeable and less believable (O’Barr and Conley, 1976). However, witnesses are perceived as more competent if their accent is standard English.

The nature of the witness’s evidence is important. Posi­tive identification has a greater impact than negative tes­timony and identification.


Witness confidence

Juries are also influenced by the confidence of the witness, though research has shown that the level of confidence of accuracy of recall is not related to actual accuracy of recall.

The coherence of the testimony is also important. In other words, if witnesses are clear and organized in their testimony it is perceived as true — including the speed of answer and specific details given. How­ever, neither factor is linked to accuracy of recall in reality.

Juries are influenced by the following characteristics of the witness: likeability, language used, accent, positive or negative testimony, confidence and coherence of evi­dence.


Perception of the evidence

The evidence presented in court can be complex, and often the trial lasts a long time. How do the jurors make sense of the trial and perceive the evi­dence presented? Pennington and Hastie (1990) have proposed the ‘story model’.

This suggests that jurors attempt to make sense of the entirety of the evidence by imposing a summary structure (‘story’). Then they seek the best fit between the verdict and their ‘story’. So, in practice, the ‘story’ mediates between the evidence and the final decision. The juror is not just hearing the evi­dence, but is trying to make sense of everything within a conceptual framework.

The juror is actively constructing a version of what happened. This is no different to how we actively construct memories and events in our and others’ everyday lives.

However, what makes the situation different to everyday life is that there are competing stories. The prosecution and the defence are each trying to cre­ate their own versions of what happened. Often, though, the failure to comprehend and recall rele­vant facts can lead to deviant verdicts. Using mock juries with a murder trial on video, Hastie et al (1983) offered five possible verdicts. In reality, only one verdict was possible from the evidence. The researchers then analysed the jurors who chose the other verdicts and found errors in comprehension (of, for example, the legal technicalities) and recall (of the witnesses’ testimonies).

Bartlett and Memon (1995) suggest a number of strategies that may help a lawyer to persuade jurors and judges of the strength of their case. The first few can be regarded as means of increasing persuasiveness in the argument:

. Vivid language enhances the impact of important testimony. Thus they regard

'He came towards me' as bland whereas 'He lunged at me with flashing eyes and a contorted grimace. . .' (p. 546) might have more effect on the listener.

. Repetition of particularly important pieces of information may be an effective strategy.

. Loaded questions such as 'Did you see the broken window?' (p. 546) contain an        implication that the unwary might accept - that indeed the window was broken.

The question 'Did you see the window in question?' contains no such implication.

. Subtle shifts in wording may profoundly influence what meaning is chosen for a sequence of events. For example, the phrases 'to sit with you' and 'to sit near you' can have rather different meanings. Nevertheless, despite this, an unwary witness might accept either.

The following strategies concern the manipulation of the credibility of the witness:

. Powerful speech styles are characterised by directness, assertiveness and rationality. In contrast, powerless speech contains a high density of 'intensifiers' such as 'so', 'well' and 'surely' together with many words dealing with hesitations such as 'you know' and 'well'. It is also characterised by polite words such as 'please' and 'thank you very much'. According to Bartlett and Memon (1995), the power­ful typifies male speech and the powerless typifies female speech. Generally speaking, males using powerful speech were regarded as more credible and much the same was true for female speakers.

. Making witnesses appear incompetent by providing, say, expert testimony that casts serious doubt on whether they could possibly have seen what they claim to have seen. For example, it might be impossible to see a face at a given distance in the dim lighting at the time.

The major advances in understanding powerful legal arguments have come from trying to understand the narratives that underlie lawyers' cases. Decision-making in a legal context is an example of a top-down process (Van Koppen, 1995). One can consider the hypothesis presented in court (the allegation of a crime) as preceding the fact-finding to support or reject that hypothesis. There is not a body of facts that is sifted through and then the most likely person to accuse selected on the basis of the facts. Quite the reverse: someone is thought to be responsible for a crime and then the facts sought that explain the accused's responsibility for the crime. The evidence verifies the charge rather than the charge verifying the evidence. The evidence, as such, though

is not the key. The important thing is the story that links the evidence together. Take the following instance from legal writing that begins with the observation that in car accidents the facts are interpretable in more than one way:

The fact that the driver did not see the pedestrian is at once an explanation of the collision in terms of accident rather than recklessness, and also a suggestion that he was not keeping a proper lookout.

(Abrahams, 1954, p. 28)

Research evidence has demonstrated that the quality of the narrative is vital in making judgements. In a classic study, Bennett and Feldman (1981) adopted a very simple methodology. They simply asked students to tell a story to other students - half of them had to tell a true story and the other half were told to invent a story. As might be expected from what we know about lie detection (Chapter 16), listeners could not differentiate between the true story and the invented story at better than the chance level. But, of course, they believed some stories but not others. So here was an opportunity to study the features of stories that made them appear truthful. Stories that were believed contained what might be termed 'a readily identifiable central action'. This provides an easily believed context for the actions of the participants. Pennington and Hastie (1981, 1986) found that the following were crucial to a good narrative:

·        . physical conditions;

·        . psychological conditions;

·        . goals of the participants.

Bennett and Feldman (1981) give the example of a story that was seen as made up by persons listening to it. It was a story about a birthday party:

Ummm -last night I was invited to a birthday party for a friend her name's Peggy Sweeney it was her twenty-fourth birthday. At the party we had this just super spaghetti dinner - you know - just great big hunks of meat and mushrooms and what not - a nice salad. And then for dessert we had a urn cherry and blueberry urn cheesecake. It was really good.

The researchers argued that this story can be broken down into a number of struc­tural elements: the connections between them being ambiguous. The two elements ­I was invited to a birthday party and last night - are joined together as a meaningful connection. Others are not:

I was invited to a birthday party - At the party we had this just super spaghetti dinner

The significance of the phrase At the party we had this just super spaghetti dinner does not lie in the context of the birthday party. The spaghetti dinner is terms of its relevance to the birthday party story. Similarly, what is the relevance of the phrase 'her name's Peggy Sweeney' to the spaghetti meal? Why mention it? Unless the hearer knows who Peggy Sweeney is, her mention just complicates the picture. If the hearer thought that Peggy Sweeney was an expert in fine food then the ambiguity might be resolved.

It is not clear what facts, logic, norms, or the like, would yield a clear inference about the relationship between these story elements.

(Bennet and Feldman, 1981, p. 78)

Story ambiguities can be of three distinct types:

Bennett and Feldman suggest that the number of ambiguous linkages of this sort (what they term 'structural ambiguities') partly determines and undermines the credibility or perceived truthfulness of the story. Indeed, they studied a number of predictors of story credibility. Of these, only structural ambiguity showed a substantial relation­ship with the credibility of the story. The length of the story, the number of actions performed in the story, the number of pauses in the story, and the length of the pauses each had no bearing on story credibility. The structural properties of the story far outweigh factors such as witness credibility, lawyer histrionics and so forth in perceptions of its truthfulness, claim Bennett and Feldman.

The birthday party story, by the way, was true despite being perceived otherwise.

    Bennett and Feldman's argument then suggests that the following areas are employed by lawyers in the courtroom when constructing plausible accounts of reality:

. Definitional tactics: the language used by witnesses (elicited by lawyers) to define pieces of evidence. Bennett and Feldman give the example of a drunk driving case in which the prosecution lawyer tried to establish the number of beers the defendant had had prior to the offence. The defence tactic was to stress the extended period of time in which drinking had taken place:

Prosecution: How much did you have to drink that evening prior to being stopped by these police officers?

(Objection by the defense)

Prosecution: Answer the question, Mr. H­

Defendant: Well, now, I was working (at) my locker the whole day on Fisherman's Wharf. I have a locker there.

Prosecution: How much did you have to drink?

Defense: May he be permitted to answer the question, be responsive. Your Honor? He started to . . .

The Court: Go ahead. Let him explain.

. Defendant: Well, it will have to all come into this now, what I am going to say. Prosecution: Fine.

Defendant: I left Fisherman's Wharf. . .

Notice how the defence lawyer shaped the defendant's testimony despite not actu­ally asking the questions. Furthermore, the definition of the drinking behaviour was extended to provide a different picture from the negative impression that would have been created by a simple tally of the number of beers drunk.

. Establishing and disrupting connections in stories: inferential tactics. The struc­tural location of a piece of evidence is made in relation to the remaining elements of the story. Bennett and Feldman give the example of the woman prosecuted for robbery. One of the salient facts was that the defendant gave her shoulder bag to a friend before committing the robbery so that she would be able to make a better robbery without this encumbrance. Under questioning, she explains that the bag kept slipping because of the leather coat she was wearing, the implication being that this was the reason for handing the bag over:

Q: You could ball the strap in your hand like a leash, couldn't you?

A: Yes.

Q: Isn't it true, Miss V -, the reason you gave the purse to D- was because you wouldn't be burdened down with it when you ran?

(Bennett and Feldman, 1981, p. 126)

In other words, the lawyer made explicit the connection between handing over the bag and the crime.

. Establishing the credibility of evidence: validational tactics. Can (a) and (b) be validated by other information and explanations, or can they be invalidated by showing plausible alternative definitions and connections between the elements of the story? An example of this is the use of objections. These serve three purposes: one is to stop prejudicial evidence being presented, a second is to build up a catalogue of errors on which to base an appeal, and the third is really to address the jury:

Prosecution: Isn't it true that in February of 1964 you were convicted of manslaughter and sentenced to twenty years in the state penitentiary? Defendant: Well, yeah.

Defense: We object to that for the record.

The Court: Overruled.

The prosecution lawyer was acting properly in terms of the location of the court studied. By objecting 'for the record' the impression is deliberately created that such questioning is on the margins of acceptability and that, as such, it should not be given too much weight for fear of inadvertently prejudicing the case.

Anchored narratives are also based on narrative theory that emerges out of cognitive psychology. This argues that evidence is meaningless without being placed into a narrative context. The story is decided upon, not the evidence. The story may have gaps but these are filled automatically by the listener. Wagenaar et al. (1993) point to some of the gap-filling in the following:

Margie was holding tightly to the string of her beautiful new balloon. Suddenly, a gust of wind caught it. The wind carried it into a tree. The balloon hit a branch and burst. Margie cried and cried.

Now this you probably took to be the equivalent of the following:

Margie, a little girl, was holding tightly to the string of her beautiful new balloon. The wind was so strong that suddenly a gust of wind caught it. The wind carried it into a tree. The balloon hit a branch and burst on a sharp twig. The loss of her balloon made Margie cry and cry.

But, equally, the story that fits the facts could have been:

Margie, a young mother, was holding tightly to the string of her beautiful new balloon. Forgetfully, she let go of the balloon. Suddenly a gust of wind caught it. The wind carried it into a tree. The balloon hit a branch and burst when a boy managed to hit it with a stone from a catapult. Margie cried and cried when the boy turned the catapult on her.

The story context determines the meaning of the central factors of the story. As a consequence, it is possible to find two radically different stories in which to set the facts to different effects. This is, after all, what prosecution and defence lawyers do to try to achieve opposite ends.

Wagenaar et al. (1993), working within the context of earlier 'good story' theories of evidence, suggest that good stories are 'anchored' into a system of general rules which are most of the time valid. This knowledge of the world helps determine the truth-value of the evidence to the listener. Evidence, in itself, does not have this truth­ value in the absence of these rules. For example, suppose that the evidence from DNA testing says that X's semen was found in the victim's vagina. This does not prove, in itself, that X murdered the woman. It does not even prove that the pair had intercourse, forcibly or not. The victim might have been a lesbian wanting a child who obtained the sperm from her friend X. She might have inserted the semen using a spatula, as she could not bring herself to have sex with a man.

Among the common sense or legal rules that firmly anchor some stories as true are the following:

·        . Drug addicts are thieves.

·        . Once a thief always a thief.

·        . Police officers are the best witnesses.

·        . Witnesses rarely lie under oath in court.

·        . If a witness has a good sighting of the perpetrator. then they will accurately identify the offender.

·        . Prosecutors usually do not take innocent individuals to trial.

·        . The associates of criminals are criminals themselves.

These rules need not have any factual basis at all.


Do not assume that good narrative accounts of the evidence which favour one side are the only requirements of a good legal case. Spiecker and Worthington (2003) studied the influence of what they call the lawyers organisational strategies on decisions made in simulated civil courts in the United States. The organisational strategies are the ways in which the lawyer chooses to organise the evidence. Two broad structures were identified - the narrative structure and the legal-expository structure. The narrative organisational structure emphasises things like describing the setting of events, describing the series of events in a meaningful and interrelated way, describing the important people in the narrative and organising the narrative in a meaningful temporal fashion. The legal-expository structure emphasises the legal requirements of the decision to be taken. These legal elements may include a description of the relevant law to the case, the nature of the burden of proof required for such cases, and the identification of the legal elements needed in order to establish the case. Both sides may take different views as to whether or not the case in question meets the requirements of proof. Of course, lawyers have more than one opportunity to make their argument. For example, they make opening statements and closing statements. So it is possible to mix the organisational strategies within a case - the opening statement could be narrative and the closing statement legal-expository. In the study in question, various possible combinations of strategies by both sides of the case were studied in terms of their effects on the jury. Broadly, it was found that both sides benefit from having the closing statement centred around a legal-expository format. That is, the lawyer should identify the legal aspects that should govern the case and offer an interpretation as to how well the evidence in a particular case meets these requirements. In terms of the overall strategy, this study showed that using a narrative opening and a legal-expository closing was more effective for the plaintiff's side than using the narrative approach for both. In contrast, the defence fared better with mixed strategy or a legal-expository approach throughout. In other words, the situation is not simply one of the narrative approach being best, it is one in which ignoring other strategies can lead to poor outcomes strictly narrative approaches were not in the interest of the defence in this case.


The role of attribution


In the same way that individuals make attributions about the cause of behaviour in everyday life, so jurors will follow the same cognitive processes in attributing the cause of the crimes. For example, Walster (1966) found that individuals vary their attribution of blame for an accident depending on the amount of damage or injury involved. If there is a large amount of damage or injury, then it is more likely that a dispositional attribution will be made. This is the belief that the individual is directly to blame for the accident, whereas a situational attri­bution tends to blame the situation as the cause of the event.


The hindsight effect

Another attribution process is known as the hind­sight effect. This is the tendency to blame the victim for what happened after the event. In an experi­ment, Janoff-Bulman et al (quoted in Sabini, 1995) gave students a story about dating which ended either with or without a rape. In the case of the rape ending, the participants tended to believe that the rape could have been predicted and placed greater blame on the victim (for example, in the way in which the woman dressed or her behaviour).


Peacock et al (1997) set up mock juries with American students during the O J Simpson trial. They noticed that the decision about guilt was based on the cognitive bal­ance theory (Heider, 1958). This involves the belief of guilt, then the interpretation of evidence to balance with the guilt or not — for example, the belief in the legal sys­tem as biased against Simpson or not. Also the role of direct experience of battered women influenced the decision.


Expert witness

Many trials employ expert witnesses to help clarify complex issues. Experts warning the jury about the reliability of certain witness evidence does reduce the trust in such evidence, but does not necessarily improve the ability to discriminate between ‘good’ and ‘bad’ evidence (Hollin, 1989). Psychologists are often used as expert witnesses, particularly in the USA. Their role can be divided into four parts (Haward, 1981)

  Experimental — the job of the psychologist here is to inform the court of relevant psychological research to the case, like the accuracy of the eye­witness testimony.

  Clinical — this involves a psychological assessment of the defendant. Is the defendant psychologically fit to stand trial or should there be a plea of ‘not guilty by reason of insanity’?

  Actuarial — this is similar to the first role, but is more of an estimate of the likelihood of certain behaviours. It is usually based on statistics.

  Advisor — in this case the psychologist is involved with the legal team and advises them. This is quite rare in the UK.


In a survey of around 200 psychologists, the most important type of psychological evidence used in courts in the UK was behaviour assessments or interviews with the defendant, followed by stan­dardized cognitive tests (Gudjonsson, 1985).


The text below outlines the ‘fors’ and ‘againsts’ of the use of psychologists as expert witnesses.



Psychologists have skills beyond the ‘ordinary person’, including the understanding of the working of memory, or the knowledge of psychometric testing. Common sense views of human behaviour are often wrong, and psychologists can correct these misconceptions. It is a risk to not give testimony (Wells, 1986).



Most psychological research is lab-based experiments, and these conclusions may not generalize to ‘real life’. Much research is able to explain behaviour in the past, but not predict future behaviour. In the study of eye-wit­ness testimony, there is often too much focus on the few mistaken identities rather than the many correct identifi­cations (Konecni and Ebbesen, 1986).


Complex expert evidence

Harrower (1998) highlights the problem for jurors of complex expert evidence, with the example of the Louise Woodward case. (Woodward, who is British, was accused of murdering the baby son of the fam­ily for whom she was working as an au pair in the USA.) Both defence and prosecution used expert medical opinion about the death of the baby Woodward was caring for. The jury made a surprising ‘guilty’ verdict, which the judge later overturned. The jury was accused of being influenced by other factors because they could not understand the expert evidence.

Jurors sometimes convict according to what they believe is right or wrong.   For example, after the miner’s strike in 1985 in the north of England, juries con­victed few miners accused of rioting. Here the jury can be seen as reflecting social opinions about the nature of right and wrong, rather than upholding a purely legal perspective’ (McClintock, 1997, p. 123).

The perception of evidence by the jury is influenced by: its complexity, the testimony of expert witnesses, attri­butions of the cause of the crime made by jurors, and the ‘story’ they impose on the trial as it unfolds.


Prosecution versus defence

The task of the opposing counsels is to persuade the jury that their version of the events is true. There are a number of factors involved in the process of per­suasion. The general model of persuasion takes into account three factors: who is doing the persuading (the source), what they are saying (the message), and who is being persuaded (the recipient). For each factor, there will be a number of influences.

The source

Important factors here include: the use of an expert, the attractiveness of the source, and his/her trust­worthiness. This last factor is most influential if the source appears to be arguing against his/her own self-interests. Judges arguing for lenient penalties for juvenile delinquents have a more persuasive effect than drug-dealers arguing the same way (Kel­man and Hovland, 1953). Similarly a habitual crim­inal arguing for stricter sentences is more persuasive than a lawyer (Walster et al, 1966).

The message

The content of the message can include both sides or only one side of the argument. The most impor­tant factor here is the order of presentation of argu­ments and evidence. Pennington (1982) set up mock rape trials and varied the order of presentation of the arguments. In one condition, the defence case came first, followed immediately by the prose­cution. In this situation, the defence case tended to win more often. This is known as the primacy effect the importance of the first piece of information. But if there was a large interval between the two arguments (like an overnight recess), then the pros­ecution won more times. This is known as the recency effect — where the last piece of information is more influential

First speech


Second speech





Guilty (primary effect)




Not guilty (primary effect)




Guilty (recency effect)




Not guilty (recency effect)


What about the quality of the arguments used by the lawyers? This is only applicable when the individuals are highly involved (that is, they feel that it is relevant to them). Axsom et al (1987) played tape of discussions about prisoners and probation. The researchers varied the level of involvement of the participants and the quality of the arguments, (with the audience cheering or booing on the tapes) Those participants with low involvement were more influenced by the audience than the quality of the arguments.


The longer the trial, the greater the advantage to the more recent case; the shorter the trial, the greater the advantage of the case presented first (Lind and Ke, 1985).



The recipient

The key variable in persuasion here is the latitude of rejection or acceptance. In other words, how large an attitude change is the recipient being asked to make? The smaller the change, the more likely it is that persuasion will be effective. So where the guilt appears obvious to the jury, it is very difficult for the defence to persuade them because ‘not guilty’ is out­side their latitude of acceptance.


American Vs. British system

British and American trial procedures are different despite both being based on the broad adversarial strategy (Collett and Kovera, 2003). There are many differences between the two. For example, in the British system, the lawyers are confined and are not free to roam around the courtroom while presenting their case; the opening statement from the defence is given after the other side has presented its case and not right at the beginning of the trial; objections from lawyers are not dealt with in the presence of the jury; British judges are more active in the general flow of evidence during the trial than American judges who may be described as being more reserved.

All of this led Collett and Kovera to the view that these differences in the demeanor of both judges and lawyers in the two systems may have consequences for how the proceedings affect the jury. One possibility is that the process of persuasion in the two systems is different.

Modern theories of persuasion suggest that there are two methods by which informa­tion is processed. One is the central route in which people actively process all the information that is pertinent to their situation. Since this is a relatively cerebral and rational process, the quality of the arguments determine the level of persuasion. The peripheral route involves considerably less effort since it involves relatively simple decision-making rules or procedures when coming to a decision. This route also involves the use of peripheral cues. For example, in the peripheral to persuasion, things such as the status of the person making the argument affects acceptance of that argument. Distractive US courtroom environments would encourage the peripheral route to be more influential, say on the jury, than the more orderly British system which would favour the more central route to persuasion. On the other hand, the greater level of involvement of the British judges may mean that jurors are more influenced by their non-verbal cues concerning the case than would be a jury with an American judge.

In an experiment testing this possibility, Collett and Kovera (2003) set up mock trials some of which followed the British ways outlined above and others followed the American way. All other things were standard to all of the trials. The amount of non-verbal behaviour expressed by the judge was varied as well as the strength of the evidence in the trials. Those who were subject to the British-style trials could remember the evidence presented in the trial better than those who experienced the American style trial. However, there was no evidence that the British style trial allowed the jurors to be more influenced by the stronger evidence than did the American style trial. The non-verbal cues given by the judge were clearly drawn attention to by the British style procedures since participants rated the judge's non-verbal cues as more salient.

There was also evidence that the British style trial resulted in the jury being more confident in their verdicts. However, the study failed to demonstrate that the two sys­tems differentially affected the trial outcomes. The study does not show the superi­ority of one system over the other. The strengths of the British system in terms of allowing the jury to focus unfettered on the evidence are offset by the apparently greater risk that non-verbal signals from the judge will affect the jury.




Dennis Howitt (2006) Forensic and Criminal Psychology, Pearson Prentice Hall, ISBN 0-13-129758-9





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