Forensic Psychology For Dummies (162 page)

Particular consideration of cognitive and emotional functioning especially in school; matters such as impairment of attention or social alienation can be important.

Corroborative information from associates and other family members.

Any post-traumatic symptoms.

Behaviour of the victim that relates directly to the presence of the perpetrator.

Linking Criminal Cases

If a court can be convinced that a series of crimes is the work of one individual, those crimes can be tried together because of what’s called
similar fact evidence.
This phrase means that evidence that convicts a person in one case, implicitly convicts him for the others. Taken together, this approach can greatly strengthen the prosecution of an individual. The courts are therefore very concerned that similar fact evidence is extremely strong so that innocent people aren’t convicted because of conjecture.

The aspects of linking cases in an investigation that I describe in Chapter 6 are also relevant for the courts, but are applied much more stringently when used as evidence. They require that distinct aspects of the actions in crimes exist, or some definite features of the culprit that are so specific that they can be characteristic of only one individual. The parallels to fingerprinting and DNA evidence are clear, but in those cases science has established that the fingerprint and DNA of each person is unique – the same can’t be said for patterns of behaviour.

In order to establish that the actions in a series of crimes are distinctive enough to have been produced by a particular person, information needs to be obtained about the prevalence of those actions, singly and in combination. The expert can then use these ‘base-rates’ to assess how different the behaviour is from what typically happens in similar crimes. Sometimes (although much more often in fiction than in reality), a criminal does something in each of a series of crimes that’s so unique that it’s regarded as a sort of ‘signature’.

Certainly, some serial murderers have left something distinct, like a playing card at each murder scene, or burglars who always bought a new jemmy to open windows with thus leaving new marks each time. But evidence of these signature actions is unlikely to be found at every crime scene for a serial offender. Therefore, more complex searches for distinctive aspects of patterns of behaviour have to be carried out if the case for similar fact evidence is to be established in court.

Chapter 20

Ten Cases in Which Forensic Psychology Was Crucial

In This Chapter

Illustrating forensic psychology in action

Showing how the contribution can be powerfully simple

Setting up experiments to test particular legal issues

Psychology makes the clearest and most direct contribution to the legal process when it relates to specific cases. Although forensic psychologists do much more than just give evidence in court, the cases that I describe in this chapter reveal the many different ways in which psychologists contribute to court decisions affecting the lives of individuals.

I was personally involved in a couple of these cases. I include these because sorting out the complexity of a legal case, and summarising key aspects of it in a few paragraphs, can be very difficult if one isn’t actively involved in the process.

Considering the Effects of Media Accounts

One of the earliest uses of modern psychology in court is still relevant today, and it concerns the influence of accounts in the press of matters relating to an ongoing trial. This event happened in 1896, and so nothing much has changed!

Baron Albert von Schrenk-Nortzing was a German physician who devoted a lot of his time to examining psychics and related paranormal phenomena. As part of these studies, he became aware of the ways in which memory can be distorted by events that intervene between the things remembered and the recall of those events. This subject would be an active area of psychological research a century later (as I discuss in Chapter 4), but at the time such a claim was a challenge to conventional views of how memory operated. The Baron pointed out that his finding was particularly important when evaluating the reports of witnesses.

In a case of great public interest, a man from Munich was accused of murdering three women. Then, as now, press coverage of the case was widespread and speculation abounded about what had happened and who was involved.

The Baron argued in court that witnesses were likely to have confused their actual memory of what had happened and what they’d seen with ideas they may have gleaned from the newspaper accounts. He even coined a rather grand term for this effect, calling it
retroactive memory falsification.
However, the court disregarded the Baron’s evidence and the defendant was found guilty.

Legal systems in many countries now acknowledge that reports and comments about events and especially about suspects can influence juries. Therefore, laws forbid comments to be broadcast or published that may influence them. These
sub judice
laws make it illegal to comment on a court case before it’s completed. Straightforward reports of what happens in court are allowed but, for example, speculation on the character of the accused would be regarded as ‘contempt of court’.

This law only applies, however, after a person has been charged with a crime and the court proceedings have started. In the US, the freedom of the press is regarded more highly than the possibility of distorting a jury’s memory and so the
sub judice
rules are much more lenient. Consequently, cases still occur today for which the Baron’s opinion would be relevant.

Determining Whether a Convicted Murderer Is Telling the Truth

Hugo Münsterberg was a highly regarded psychologist in the US at the turn of the 20th century. He was aware of the many contributions that scientific, experimentally-based psychology could make to legal processes and wrote popular articles and academic accounts of his work for the courts. He introduced many of the issues that forensic psychologists still deal with over 100 years later, including false confessions, distortions in eyewitness testimony and determination of lying. At the time, however, he wasn’t taken very seriously.

In 1908, he published a controversial book called
On the Witness Stand
, in which he describes his experiences of providing evidence in court cases. The book advocated much more use of psychological scientific cases in legal proceedings, but many years passed before evidence from psychologists became accepted in court. Indeed, many of his recommendations have still to be taken up.

One example of his account, in his own words, illustrates how innovative his thinking was. In this case, one convicted murderer was giving evidence against another and Münsterberg was seeking to determine whether this man, who claimed that he’d become religious and was now telling the truth, was lying.

Münsterberg first made sure that the witness believed in the powers of the psychologist:

I told the witness directly that I had come to examine his mind and find out what was really at the bottom of his heart . . . I began with some simple psychological tricks . . . which were naturally unknown and somewhat uncanny to the witness . . . and soon he was entirely under the spell of the belief that I had some special scientific powers.

Then I began with a real experiment. I told him that I should call at first fifty words, and each time, when he heard a word, he was to name to me as quickly as possible the first thing which came to his mind on the hearing of the word . . . My first word was ‘river,’ he associated ‘water’; then ‘ox,’ he said ‘yoke’; ‘mountain,’ he said ‘hill’; ‘tobacco,’ he said ‘pipe.’ All the interest thus seemed to belong to the choice of the words, and he saw that I wrote his answers down. But the fact is that I did something else also; I measured in fractions of a second the time between my calling the word and his giving a reply. Between his hearing of the word ‘river’ and his speaking the word ‘water,’ eight-tenths of a second passed; between ‘ox’ – ‘yoke,’ six-tenths; between ‘tobacco’ – ‘pipe,’ eight-tenths. On the whole, seven to eight-tenths of a second was the very short standard time for those associations which represented familiar ideas.

Now, there were mixed in among the fifty words many which had direct relation to his criminal career and to his professed religious conversion – for instance, the words confession, revolver, religion, heaven, jury, death, Bible, pardon, railroad, blood, jail, prayer, and some names of his victims and of his alleged accomplices. Let us not forget that he was fully under the belief that I had a special power to discover from his spoken words the real tendencies of his mind. If he had had anything to hide, he would have been constantly on the lookout that no treacherous word should slip in . . . and yet, however quickly he might have done it, it would have taken at least one or two seconds more; and he would have used the longer time the more freely, as he had no reason to suspect that time played any part in the experiment.

But the results show the very remarkable fact that the dangerous words brought, on the whole, no retardation of the associative process . . . Even the names of his accomplices and of his victims awoke associations in less than nine-tenths of a second. The fact that these associations were produced by the witness in the minimum time, which made deliberation impossible, while he was convinced that the words would unveil his real mind, is strong evidence indeed that this man did not want consciously to hide anything, and that he himself really believed his confession.

This quote shows Münsterberg using the psychological procedure of measuring reaction time to determine how much the witness needed to think about his answers before uttering them. Münsterberg thought that the longer the reaction time the more the person was trying to develop in his mind an appropriate answer. If he gave a very quick answer then he was not trying to invent anything at all and so his answers could be trusted. Like any good scientist Münsterberg also made sure he had some comparison figures for the individual in question under neutral conditions. Psychologists still use similar explorations today, but with much more sophisticated equipment. However, I’ve not heard of this being used as an assessment of the trustworthiness of a witness in court.

Recreating Events to Test a Claim’s Validity

Professor Lionel Haward is primarily responsible for establishing the use of psychological evidence in UK courts. In the first major book in the UK on the work of forensic psychologists, published in 1981, he describes many of the cases for which he appeared in court.

One case that illustrates his approach of setting up studies specifically to test the validity of claims in a case, relates to a road accident in which a 14-year-old boy was knocked down by a car as he turned from a farm track onto a country road on his bicycle.

The defence of the driver related in part to the suggestion that the boy was of low intelligence and, as a consequence, had been guilty of ‘contributory negligence’. In other words, the accident was to a certain extent the boy’s own fault because he hadn’t been cycling sensibly. Professor Haward therefore tackled this claim directly: