The use of reports of memories by witnesses is common in both criminal and civil proceedings. During trials, eye-witnesses are often called to testify about what they saw, heard or perceived by their senses about events relevant to the case at hand. Such evidence must be balanced up against the total evidence of the case, but it can, and has, been the deciding factor in the determination of guilt in criminal matters, and liability in civil matters. But how reliable is memory evidence? It seems that such evidence has to be considered as fallible and open to contesting, as scientific studies have shown that witnesses may reconstruct past memories in accordance with other systems of beliefs, which may affect the veracity of the reports, particularly where trauma is involved.
M. Howe and L. Knott, "The Fallibility of Memory in Judicial Processes; lessons from the past and their Modern Consequences," Memory, vol. 23 (5), 2015, pp. 633-656, give a very comprehensive outline up until 2015 of many cases showing the fallibility of memory and "false memories," such as involving alleged sexual abuse, especially child sexual abuse, recalled years, if not decades, latter from the alleged event.
Behind this fallibility lies the physiology of memory, where long-term memory occurs through the maintenance of neurons, brain cells, and their synaptic connections, the electro-chemical connection between these brain cells. Every time a long-term memory is recalled, there is a reconstruction of these brain connections. This creates, as with any physical process, the probability of error, faults, or reconstructions and possible embellishments, particularly in the light of recent experience and memories, involving trauma. And the more the event is recalled, the greater the probability of this error process occurring. Psychologist Elizabeth Loftus is the leading US psychological researcher, who has shown that eye-witness memory is more fallible than once was thought. Various experiments were done with subjects viewing film clips of car accidents, and it was found that the accounts of the events viewed could be influenced even by the phrasing of the follow-up questions. Professor Loftus also argued in the so-called "memory wars," where in the US this question of reliability was hotly debated, that many "recovered memories" were often achieved during hypnosis, and the patients are open to suggestion during such sessions. Thus, there have been recovered memories of alien abductions and witnessing of human sacrifices during Satanic rituals, which most likely did not occur, at least the alien abductions.
Courts handle the issue of the reliability of memory with caution. As noted in the High Court case of Graham v The Queen, courts should be concerned with memories which are "fresh," or generally recent. Those occurring years, if not decades ago, need to be enlivened by some special feature that bestows a sense of reliability. Thus, in a case I heard of, that did not go to trial, a young man at an office party was alleged to have engaged in a drink spiking. He tipped an alcoholic drink into the water glass of a companion female, who was a non-drinker. He alleges that he then drank from the glass, with the female observing it. The business which held the function had made the disciplinary complaint, which the female agreed to. The drink spiking case of course collapsed as spiking requires that the innocent person does not know the drink has been spiked, and the spiker is not supposed to drink that alleged spike drink! What is interesting in the case was that management brought the issue almost 12 months after the party. There were said to be witnesses who observed the drink issue, interviewed 12 months later. So, almost 12 months after an event like this, people will allegedly remember an incident like this, when they themselves have been drinking alcohol and are unlikely to have been paying attention! The case collapsed, and would not have made it to court.
The take home lesson, is if memory issues are going to be an issue for you in some matter, take backup, make documents, various recordings, notes, photographs and the like. Witnesses would be good, but they need backup as well.