Forensic Psychology For Dummies (116 page)

A similar problem may arise (that may lead to a jury giving a guilty verdict) when a person is tried for a number of similar crimes all together. The reason may be to save time and money, but as you’d expect, if a person is charged with a string of offences the jury is likely to be rather suspicious about him and more likely to convict. For this reason again intense debate takes place, before the court proceedings begin in front of the jury, as to whether cases are sufficiently linked to warrant being presented together.

Another problem is when jurors are at risk of finding out evidence that the judge decides isn’t admissible in court. In the US, this evidence often comes from newspaper reports before or around the time of the trial. (In recent cases in the UK this has been from Googling details on smartphones!) In the UK and many other countries, after a person is charged with an offence the offence becomes
sub judice,
meaning that it’s now in the hands of the justice system and no one can mention anything that may influence potential jury members (which before selection can be almost any member of the general public). With its stronger commitment to a free press, the US doesn’t have such strict
sub judice
rules.

The judge instructs jurors to put all emotional concerns out of their minds and to review the facts as objectively as possible based on the way they’ve been determined in court. They’re also told to ignore anything they’ve heard about the case except the evidence they hear in court, and yet when jury decision-making is looked at closely, research often finds that jurors are unable to ignore what they may have heard or to only pay attention to the facts as presented in court.

Making sense of the evidence

Particular challenges arise for a jury when it has to consider scientific or technical evidence. The following matters are examples of the sort of things juries can have difficulty dealing with:

The probability of an occurrence.
For instance, if an expert says that 1 out of 100 cases would randomly produce the results found in this particular case, members of the jury may not be able to determine whether this means the results found are so unusual that they could have just happened by chance, or are so unusual that they have to be significant for the case. By contrast, eyewitnesses stating with confidence that they saw the defendant at the crime scene may be taken as strong evidence, even though (as I discuss in Chapter 4) such a confident assertion may sometimes have little validity.

Large amounts of information.
If a lot of information is available, especially when that information is complex scientific information, jurors may feel well-informed but then find it very difficult to disentangle the different aspects of that information and come to a conclusion.

Requirement for a control group.
Often, jurors aren’t aware of the need for some sort of comparison against which to assess any scientific conclusion (what scientists call a
control
group of people or objects to whom the procedure hasn’t been applied). For instance, being informed that a particular chemical was found in people who’d died would only be suspicious if the chemical wasn’t found in people who hadn’t died.

Cross-Examining the Psychology of Cross-Examination

In this section, I examine the psychology involved in the questioning of witnesses in court.

Setting questions and giving answers

The legal process relies heavily on the questioning of witnesses. How well the lawyers asking questions understand the issues at hand is therefore central to how a case unfolds in court. If the lawyer goes off in a direction that the witness (whether an expert or not) thinks is misleading, getting back to what the witness considers crucial to understanding the matter at hand can be extremely difficult.

The whole legal process therefore depends on how effective the question and answer sessions are from which the evidence is drawn. This arrangement gives the lawyers considerable power in how evidence is presented to the judge and jury. They can guide the sequence in which information is presented and thus how readily it may be believed.

As a university teacher I’m used to giving lectures on topics, using illustrations wherever possible. I was surprised, therefore, the first time I gave evidence in court and discovered that I wasn’t expected to give a talk explaining my opinion and the reasons for it. Instead, the barrister led me through a series of questions as a way of revealing who I was and my opinion. Courts are rarely designed to allow easy presentation of illustrations and so most of what’s explained comes in answers to questions. This means that it’s difficult to develop elaborate explanations of subtle issues, and, as I describe in the following sections, the way the material is presented is open to strong influence from how the lawyers want to show it.

Avoiding leading questions

The rules of what’s acceptable in court are shaped to avoid unfair bias in questioning that can influence answers unfairly. The most significant of these rules is the avoidance of
leading questions.
For example, a lawyer asking a witness, ‘Did you see a red car?’ is normally considered improper, because the question assumes that a car was involved and that it was red. A more acceptable question would be, ‘Did you see any vehicles?’.

The assumption is that leading questions imply facts and may therefore influence a jury even if no evidence exists for those facts. They may also encourage witnesses to give positive answers because of the intimidating pressure of the legal rituals (which I discuss in the earlier section ‘Examining existing legal rituals’).

These assumptions about leading questions are valid and can be taken a stage further by building implicit suggestions into questions. In one study, when people were asked to estimate the speed of a vehicle, they gave much higher estimates when the question mentioned the cars ‘smashing’ into each other than when the phrasing was ‘contacting’ each other. Witnesses are also more likely to report seeing broken glass when the word ‘smash’ is used, even though none was present. This research relates to the easy influencing of memory that I explore in Chapter 4.

Although leading questions are improper when lawyers are questioning witnesses from their own side (for example, the prosecutor questioning prosecution witnesses), such questions may be tolerated, indeed may be explicitly permitted in some jurisdictions, during cross-examination of the opposition’s witnesses, sometimes causing distress and confusion in the witness.

Variations on leading questions are also acceptable in the forms I discuss in the following list. Certain aspects of these questions, however, raise problems because although they may seem innocent enough they may implicitly distort the given answers or mislead the jury. These types of questions include:

Directed questions.
‘What colour cap was he wearing?’ is a question that assumes he was wearing a cap. In addition, it doesn’t deal with anything else he was wearing and so draws attention to only one aspect of the clothing. Witnesses are likely to be comfortable with such questions, because they can appear supportive and encouraging, and so are more willing to answer them confidently even when their memories are less than clear.