In 1979 Loftus looked at how violent crime, in particular crime involving the use of a weapon by the perpetrator can reduce the accuracy of an eye witness’s recall of events. This is known as ‘weapon focus’. Loftus tested this effect in a single experiment. Each participant sat alone in a waiting room, and from another room heard a pre- recorded argument. The participants were unaware the experiment had begun. A man entered the room drew attention to himself and left. Each person was then asked to give a description of the man, however one group witnessed the man carrying a pen, for the other group the confederate was holding a knife. The group who observed the situation involving the pen were able to give a much better description of the man than in the case of the knife. It was concluded that the presence of the weapon was responsible for this. A possibility for this is that a person witnessing a crime which involves a weapon such as a gun or a knife focuses on the weapon as they perceive it to be a threat to themselves and this causes a high level of arousal. When this happens there is an immediate release in the body by the adrenal glands of adrenalin, if the threat is still there after 2 to 3 minutes, as could be the case if in a bank at the time of an armed robbery, the adrenal glands release cortisol, which can have an effect on a person’s ability for accurate recall of an event.
Research has been conducted which refutes this (Brown and Kulik 1977), which suggests that a high level of arousal can increase a person’s ability to recollect an important event with increased accuracy. However it is important to make a distinction between events that can be positive for someone’s life such as the day your child was born, events that may have been witnessed on television, for example the terrorist attacks on the world trade centers, or being an innocent bystander at the time of an armed robbery.
Loftus has been criticised for aspects of her work, particularly for the research being artificial, however it has shown how a person’s ability for accurate recall of an event can be influenced.
Many other researchers have questioned the reliability of eye witness testimony and identified several factors which can affect a person’s ability to accurately recall a crime, notably Brigham & Malpass (1986) who suggested we make more errors when the suspect is a different race to the witness. They concluded that we are better at being able to recognise our own race.
Another explanation for the inaccuracy of recall is that if our memory of an event is sketchy we have a tendency to use our schemas and stereotypes to fill in the gaps. This is known as reconstructive memory, we reconstruct events by combining parts of the event that is real with our schemas which are stored in long term memory. One of the first to investigate the accuracy of memory was psychologist Frederic Bartlett (1932). He asked a subject to read a story entitled ‘War of the ghosts’ an old legend about an Indian hunter. The person then had to tell the story to another subject who had not heard it before, the second person then told it to another person, this carried on until ten people had heard it. Bartlett found that by the end, whilst a few basic elements of the story remained, many new ‘bits’ were added as each person along the way in order to make the story more complete added new parts. This additional information came from each person’s knowledge from how they see the world.
The findings from the all the research shows how problematic dealing with eyewitness testimony can be, for both the police who interview witnesses and for the courtroom where the testimonies of witnesses have a big impact. An obvious implication for the courts is dealing with suspects where eyewitness testimony is the main source of evidence.
Throughout history it is possible to find hundreds of examples where wrongful convictions were the result of faulty eyewitness testimony. This has a profound effect on the life of an individual who suffers a miscarriage of justice, and also that person’s family. In severe cases it has cost some people their lives in countries where capital punishment is still used. It has implications for the authorities who over the years have had to pay very large sums of money to people who have spent a long time in prison even though they were innocent. Also there are huge costs involved in trying to catch offenders and imprison them, the police operations, and also the cost of taking people to court, and in every case of wrongful conviction, it means the original perpetrator of the crime is still at large and able to perhaps commit further crime.
In order to eradicate possible miscarriages of justice law enforcement agencies are using techniques to make a witness’s interview more accurate. Standard police interviewing in the past has used closed questioning, and excessive interruption. The Home office acted upon psychological research (Geiselman et al 1984) and implemented changes to the way police interviews are conducted. The new technique is known as the cognitive interview. This aims to give the witness the feeling of greater control in the interview.
Interviewees are first asked to recreate the context of the crime, and then the witness is asked to talk of anything they remember in free recall, regardless of whether they perceive the information to be important or not. It is hoped that in cases where there are multiple witnesses, each witness will be able to give different details, and the police can piece together all the fragmented details to arrive with a clearer picture of events. The eyewitness is also asked to talk about the event in a different order or reverse order, and try to recreate the situation from different perspectives. This all helps to retrieve the event without the possibility of leading questions.
Fisher et al (1987) introduced new elements to the cognitive interview, and devised the enhanced cognitive interview. The basic framework of the original technique was kept with the introduction of some new elements. The cognitive interview was found (Geiselman et al 1985) to produce a greater degree of accuracy than the previously used standard police interview. Research has been conducted (Fisher, Geiselman and Amador 1990) which shown the enhanced cognitive interview produced better results than the basic model, especially when interviewers had been trained in the methods.
The use of identity parades to pick out possible suspects has often proved crucial in the courts arriving at a guilty verdict. However methods used have also been questioned. Traditionally a victim or other eyewitness will look along a line of people who should have roughly the same characteristics and asked to see if they can see the perpetrator of a crime. There are potentially some problems with this methodology.
One problem is identity parades are often conducted a while after the crime was been committed, and a person’s recollection of events can decay over a period of time, as well as this, faced with the pressure of feeling like they have to pick someone, may lead to picking out someone they are not entirely sure committed an offence. If it is the victim asked to identify a suspect, they could be in high state of emotional arousal. They could have the stress of coming close to a person who perhaps assaulted them, also there could be anger involved, and they may pick anybody on the basis they want someone prosecuted for what happened to them.
Identity parades could be perhaps made more reliable by introducing new methods. One such method could be to introduce the line up sequentially, this may ease some of the pressure involved. Also the officer conducting the parade shouldn’t be aware if the main suspect is present, this could stop anybody perhaps being led to one member of the line up. It could also be mentioned to the person who is trying to identify the perpetrator that the suspect may not be in the line up, this would stop the person feeling like they have to pick someone.
It is clear from all the research there is a big margin for error in eyewitness testimony. Whilst jurors are still highly influenced by a confident eyewitness, more cases are able to be solved with more scientific methods such as DNA. However all parts of the justice system should be trying to eliminate potential problems with the testimony of an eyewitness. Perhaps cases should not go to court when the main evidence provided is eyewitness testimony.
References
Harrower, J (1998). Applying psychology to crime. London: Hodder & Stoughton. P152-153.
Sears, Peplau, Taylor (1991). Social psychology. 7th ed. London: Simon & Schuster. p55.
