The problem with the key evidence in the Lockerbie case is that it ignored discoveries made by psychologists more than 100 years ago. When the Scottish police resume their inquiries into the bombing of Pan Am Flight 103, they will be reminded that the evidence that condemned Abdel Baset Ali al-Megrahi was probably based on a vague memory that somehow became convincing enough for the court to convict.
By dropping his appeal so that he could die at peace at home in Libya, al-Megrahi removed the opportunity of having the challenges to the evidence against him revealed in court for all to see. The furore over his release masked the debate about whether he really was the man who planted the bomb on Flight 103 and has drawn attention away from the significance of the eyewitness testimony provided by Anthony Gauci, a Maltese shopkeeper.
It was Mr Gauci’s claim that the man who bought clothes resembling those found in the suitcase with the bomb was indeed al-Megrahi, which was the foundation of the evidence against him. Yet many studies since those of the late 19th century of the psychology of memory have raised doubts about witness testimony. They raise important questions about the validity of what Gauci eventually claimed in court he thought he had remembered. This was the conclusion I came to when I was instructed by al-Megrahi’s solicitor to review Mr Gauci’s testimony. With the assistance of two colleagues, I produced a 102-page report that examined 96 statements surrounding Mr Gauci’s claim that al-Megrahi had bought the clothes in his shop before December 21, 1988.
There were a number of problems with Mr Gauci’s memories, not least in his identification in court, 13 years after the bomb exploded, that the man standing in the dock, al-Megrahi, had bought the clothes. Police had asked Mr Gauci more than ten times to pinpoint the person who came to his shop: at various times he identified various different people.
Many experts have pointed out how unreliable dock identifications are. They are a form of leading question which suggests that the person who has been brought to justice is very likely to be guilty.
On February 15, 1991, two and a half years after a man possibly had visited his shop, Mr Gauci was shown 12 photographs and asked if he recognised the purchaser. At that stage in the investigation the police were focusing on al-Megrahi as the likely culprit. They, therefore, had a lot invested in Mr Gauci choosing al-Megrahi from the photographs. There is a considerable psychological research to show that people can be influenced in their judgments by subtle cues from others around them. So it seems very likely that inadvertently Mr Gauci could have been influenced to choose the photograph the police wanted.
We tested this possibility by running an experiment with two interviewers. Both were told to ask a random selection of people which of the people in the 12 photographs the police had used was likely to be the Lockerbie bomber. They were told to be careful not to indicate who they thought the culprit might be. Interviewer A was told that picture 8 was the culprit and interviewer B was not told anything. Of the 20 people interviewed by B none selected picture 8. Of the 36 interviewed by A, 15 chose picture 8. This small study, with the actual material used by the police, accords with many other explorations of these issues and many cases in which confident eyewitness identification has later proven false.
The police and court seemed to hold an uninformed, naive view of how human memory works. The popular misconception is that memory is like an old-fashioned photographic plate that records what happens, but then slowly fades with time. There even seems to be the assumption that the plate can be dusted down and put in a bright light to reveal more clearly what was there all along.
This certainly was the basis of the claim that Mr Gauci’s memories of an alleged all-important shopping spree actually improved with time as he thought more carefully about the event. But all the evidence is that, unless the event is of great emotional significance and attended to very carefully at the time, it fades from our minds very quickly. So for a shopkeeper to claim he had a memory of what clothes were bought and by whom, when the purchases and purchaser were unremarkable, seems very unlikely, especially so long after the event.
Some of the most important statements by Mr Gauci were made on January 30, 1990, a good two years after the bomb went off. Over and over again it appears that Mr Gauci is keen to do everything he can to remember something that will be of assistance. This leads to a development of what he thinks he remembers when prompted by the police interviewer. We identified at least 20 crucial aspects of Mr Gauci’s memory of the purchase of the clothing that varied considerably over the years from one statement to the next. How the purchaser left the shop, whether he got into a taxi or not, all of these details are vague to begin with but become more precise under police questioning, even though the initial interview was at least ten months after the purchases were reputedly made and subsequent statements were two or more years later.
The evidence in court many years later still gives the impression of confident clear memories. But the earlier statements put these in different light. For instance, Mr Gauci initially claimed the man bought no shirts, but ten years later said in court that he had. In early statements he said that the purchase was well before Christmas as there were no Christmas lights in the shop, but by the time he came to give evidence in court the lights were clearly present.
Whole volumes have been written in recent years on how readily people can come to believe that they remembered things that never occurred but which were actually suggested to them in earlier interviews. There is no simple relationship between how confident a person is in what he thinks he remembers and how accurate that memory is. Yet this psychological truth was ignored by the court that convicted al-Megrahi.
David Canter is a professor of Psychology at the University of Huddersfield and the author of Investigative Psychology: Offender Profiling and the Analysis of Criminal Action.