MEMORY IN LEGAL CONTEXTS: REMEMBERING EVENTS,
CIRCUMSTANCES, AND PEOPLE
-eyewitness testimony: a recollection of the actions, circumstances, and the people
involved by witnesses and/or victims of a crime.
-Crimes involving a single witness or victim, additional material or circumstantial
corroborating evidence are often not available.
-Scientific research on eyewitness testimony draws heavily upon the fields of
cognitive psych. (perception, short and long term memory, thinking, decision making)
and social psych. (influence of social variables upon human behaviour i.e,
conformity, self-presentation, attitudes)
-Variables related to eyewitness testimony: the effects of witness age, time delay
between observation and report, repeated and suggestive questioning procedures,
mental rehearsal, and identification decisions.
-A useful distinction frequently made by researchers in the area of eyewitness
testimony is that between “system” and “estimator” variables
-System variables are those features of the legal system that can alter the reliability of
eyewitness testimony – i.e.: kinds of identification procedures used.
ob/c these features can be controlled, changes can be made to them to improve
the reliability of eyewitness testimony.
-estimator variables refer to the situational and personal characteristics inherent in a
event, its witnesses and consequences
owe have no control and must estimate the magnitude of their effects
oie: a witness’ age is unknown to be related to identification performance, but
the age of witnesses cannot be controlled
oie: the lighting at the scene of a crime is related to accuracy of descriptive
testimony, but its effect upon a single witness can only be estimated.
Basics of Memory and its implications for Eyewitness Testimony
-most judicial systems have developed rules of evidence, whereby the admissibility of
evidence is assessed based in part on its reliability
-How accurate or reliable is eyewitness testimony?
-we must first assume that an event was indeed witnessed and perceived as to its
meaning (encoding stage), and then processed in such a way (storage stage) as to
make it available later through one of several kinds of memory tests (retrieval stage).
important to recognize the possibility of several stages or types of processing b/c
the greater then # of stages and cognitive activities, the greater the opportunities for
error or low reliability.
-Memory is an active process where information is located
-We never actually see anyone’s memories, instead we call memory as a product
of a sequence of unobservable cognitive activities
-K. v. Keegstra (1992) the Alberta Court of Queen’s Bench ruled in favor of
allowing written classroom notes written by students years earlier to be admitted
in place of the students’ own personal memories if the students themselves could
not remember that statements made by the accused (their teacher)
othis was known as “past recollection recorded” info. removed from the
witness’s current memory and different from a currently available memory
record that has merely been refreshed by reviewing a set of notes.
-different kinds of memory tests at the retrieval stage can influence how well
something is remembered.
-Ex: essay recall memory v.s multiple choice recognition memory
-Another kind of retrieval test is the identification of a suspect in a “show-up” -- a
photospread of people’s pictures from police files or a live line-up -- that includes
the actual suspect and foils and distracters.
WHAT THE LEGAL SYSTEM EXPECTS FROM US
-eyewitness testimony is admissible in court as opposed to fingerprints which are
indirect or circumstantial evidence
-jurors and judges are expected to remember the evidence presented w/o benefit of
written notes or tape recordings
-the amount of time a witness has to observe a perpetrator and the length of time
between the witness’s observations and the identification of a police suspect
(called the retention interval) are two common factors to consider in crimes
involving eyewitness testimony
-increasing the duration of both variables has opposite effects upon reliability --
longer observation times will increase reliability, while longer retention intervals
will decrease it.
-When memories have been tested, some analyses of reports by witnesses to actual
crimes have indeed found high levels of accuracy following delays of up to 6
months or more.
-Ex: Adolph Beck was mistakenly identified by 14 witnesses as being an English
scam artist who had swindled them of their jewelry and money.
-Some variable have consistent effects upon eyewitness performance such as
centrality of info. to be recalled such as a weapon or hold-up note that are more
likely to be remembered correctly than are other variables
-In general, the greater the emotionality of an event, the greater the magnitude of
ELICITING INFORMATION FROM VICTIMS AND WITNESSES
-information is the raw material with which a case is built.
Verbal Recall Testimony
-in the initial stages of an investigation the information obtained is likely to come from
the witnesses’ responses to “W5” interview –type questions – “Where and when did
the event occur?”, Why were you there?” etc, asked by professionals in the justice
system such as police investigators , social workers, lawyers, and insurance
-Origins of the current state-of-the-art investigative interviewing procedures can be
traced to 3 research areas: hypnosis, encoding specificity, and misleading post-
oFranz Mesmer “mesmerized”
oMesmer was convinced that (just as Newton’s gravity explained the magnetic-
like attraction between objects) animal magnetism explained his ability to
influence other people’s behaviour from a distance “animal magnetism”
oHe apparently cured minor ills by waving and lying his hands to induce a
sleep-like trace on those willing to participate.
oNo one disputed the apparent effects of this procedure, but scientific
investigators placed the explanation of those effects on the mind’s of
Mesmer’s subjects rather than in the hypothetical mechanism of animal
oThere is still debate as to whether hypnosis represents a distinct state of
consciousness or if it merely occupies an extreme position along some
continuum of suggestibility – still hypnosis is a well-established technique,
widely used around the world in therapeutic settings to enhance the recall of
witnesses in police investigations.
o“hypnotically refreshed testimony” -- term used to describe the fact the people
often recall more accurate details about an event under hypnosis than they do
in a “normal” state.
-based on some implicit and unsupported beliefs about memory:
1. hypnosis allows access to memories beyond what normal retrieval processes can
2. that memories are retained permanently in the brain uncontaminated by additional
experiences, thoughts and misleading information
-in reality, hypnosis incorporates a combination a normal retrieval processes (ie:
relaxation instructions, increased motivation, etc) that can assist a witness to recall
additional material beyond the first police interview – some of which is incorrect
-the primary arguments against the use of hypnosis in forensic settings arise from
demonstrations that hypnotized witnesses more frequently recall incorrect or false
information during hypnosis than do non-hypnotized participants and that such
information can be implanted through suggestive questioning techniques – a negative
triple whammy against the use of hypnosis
-as a consequence of the vulnerability of reports gained through hypnosis, such
evidence is not usually admissible in Canadian courts, but can be admitted
-alternative interviewing technique Cognitive Interview
Circumstances, and people eyewitness testimony: a recollection of the actions, circumstances, and the people involved by witnesses and/or victims of a crime. Crimes involving a single witness or victim, additional material or circumstantial corroborating evidence are often not available. Scientific research on eyewitness testimony draws heavily upon the fields of cognitive psych. (perception, short and long term memory, thinking, decision making) and social psych. (influence of social variables upon human behaviour i. e, conformity, self-presentation, attitudes) Variables related to eyewitness testimony: the effects of witness age, time delay between observation and report, repeated and suggestive questioning procedures, mental rehearsal, and identification decisions. A useful distinction frequently made by researchers in the area of eyewitness testimony is that between system and estimator variables. Basics of memory and its implications for eyewitness testimony. Most judicial systems have developed rules of evidence, whereby the admissibility of evidence is assessed based in part on its reliability.