SYSTEM VARIABLES
Variables controlled
within an actual court case are system variables (Wells, Memon, & Penrod,
2006). System variables are divided into two categories; interviewing
eyewitnesses and identification of suspects. Interviewing eyewitnesses is the
process that involves recall memory and identification of suspects involves
recognition memory (Wells et al., 2006).
Interviewing Eyewitnesses
Research on interviewing eyewitnesses began in the early 1900s (Wells et al., 2006). Alfred Binet was the first to study suggestibility and William Stern initiated eyewitness research in Germany (Wells et al., 2006). Modern day research is heavily influenced by Elizabeth Loftus, who utilized a method of asking questions of eyewitnesses to encourage them to adopt information that was identified as misleading (Wells et al., 2006). Loftus’s style of research opened the door for experimental studies and the forms of misinformation imparted during the questioning of adult and children witnesses (Wells et al., 2006).
The Cognitive Interview
Psychologist R. Edward Geiselman developed the cognitive interview (CI) behind the influence from police officers and legal professionals who encouraged improvement in the outdated practices in police interviews (Wells et al., 2006). One of the focuses of the cognitive interview is to produce effective communication between the interviewer and the witness (Wells et al., 2006). The cognitive interview consists of several phases in which the interviewer engages and establishes a connection with the witness (Wells et al., 2006). The interviewer also encourages the witness to provide a narrative account of the witness event. This is followed by probing questions relating to the details the witness has provided (Wells et al., 2006). The goal of the interviewer is to interrupt as little as possible and allow the witness to dictate the subject matter, sequence of questioning, and maintain active listening.
To begin the cognitive interview, the interviewer attempts to build rapport with the witness. Building rapport allows the witness to be more at ease and it minimizes the discomfort and distress that is usually associated with sharing an intimate or fearful experience with a stranger (Wells et al., 2006). In addition, building rapport allows for increased accuracy by way of open-ended questioning. The optimal goal is to transfer complete control to the witness (Wells et al., 2006).
Identifying Criminal Suspects
Identifying a criminal suspect plays a very crucial part and, in most cases, is the most important eyewitness evidence presented at trial. This becomes true when an eyewitness makes the claim to have seen the suspect commit the criminal act (Wells et al., 2006). The identification testimony then becomes direct evidence of guilt and establishes a sense of accuracy in the grand scheme of whether the suspect committed the crime or not. Eyewitness testimony, regardless of whether the identification is direct or circumstantial, is looked upon as accurate by the observers if the eyewitness displays consistency and confidence (Wells et al., 2006).
Lineups
Lineups are the primary method for obtaining identification of criminal suspects (whether it is live or photographic) and involves placing a suspect among fillers, asking the eyewitness if he or she can identify the perpetrator (Wells et al., 2006). The two possible states of truth include the suspect is the target and the suspect is not the target. With only one suspect being involved in a lineup, the two states are equal to target-present and target-absent lineups (Wells et al., 2006). In a target-present lineup, two kinds of errors can be made. The incorrect rejection (making no identification) or the identification of a filler (Wells et al., 2006). Lineups are used in different variations whether it is simultaneous, sequential, double blind, or target removal without replacement (RWR) lineups (Wells et al., 2006).
Simultaneous and Sequential lineups
Simultaneous lineups are the traditional police lineup utilized for which all members are presented to the eyewitness at once (Wells et al., 2006). The witness chooses an individual in the lineup who they believe is the perpetrator or reject the identification of any of the individuals in the lineup if no one is deemed in their eyes to be the suspect in question (Wells et al., 2006). In contrast, the sequential lineup presents the lineup members to the eyewitness one at a time. The witness has the opportunity to make a decision on the individual presented in front of them before the next member in the lineup is presented if needed (Wells et al., 2006). The number of members who will appear is not disclosed to the witness. The idea behind the sequential lineup is to prevent the witness from relying on relative judgment and using the process of elimination (Wells et al., 2006). Despite a lower mistaken identification rate for sequential lineups, it also yields a lower reduction in accuracy in regards to identification (Wells et al., 2006).
Double-Blind Lineups
A detective who is aware of the person of interest usually conducts a police lineup. This person is known as the suspect. All remaining members of the lineup are considered fillers. Experiments have indicated an increase in the eyewitness identifying the suspect when the lineup is administered by an individual who believes that a particular lineup member is the suspect (Wells et al., 2006). A double-blind lineup is when the administer is not aware of which lineup member is the suspect and which members are fillers (Wells et al., 2006).
Removal-without-replacement (RWR)
A removal-without-replacement (RWR) lineup is when an eyewitness views either a six-person or five-person lineup in which one member of the lineup is removed and not replaced (Wells et al., 2006). The eyewitness is notified prior to the lineup that the target might not be present. A removal-without-replacement lineup is most effective when the memory of the witness appears to be weak (Wells et al., 2006).
Composites
The utilization of sketch artists or composite faces takes place when there is no clear suspect. The original system, Identi-Kit used line drawings of facial features on transparencies to create a composite (Wells et al., 2006). Currently, composite production systems create faces by selecting features, which will then be combined into a face (Wells et al., 2006).
Reference
Wells, G. L., Memon, A., & Penrod, S. (2006). Eyewitness evidence: Improving its probative value. Psychological Science in the Public Interest, 7(2), 45-75.
Interviewing Eyewitnesses
Research on interviewing eyewitnesses began in the early 1900s (Wells et al., 2006). Alfred Binet was the first to study suggestibility and William Stern initiated eyewitness research in Germany (Wells et al., 2006). Modern day research is heavily influenced by Elizabeth Loftus, who utilized a method of asking questions of eyewitnesses to encourage them to adopt information that was identified as misleading (Wells et al., 2006). Loftus’s style of research opened the door for experimental studies and the forms of misinformation imparted during the questioning of adult and children witnesses (Wells et al., 2006).
The Cognitive Interview
Psychologist R. Edward Geiselman developed the cognitive interview (CI) behind the influence from police officers and legal professionals who encouraged improvement in the outdated practices in police interviews (Wells et al., 2006). One of the focuses of the cognitive interview is to produce effective communication between the interviewer and the witness (Wells et al., 2006). The cognitive interview consists of several phases in which the interviewer engages and establishes a connection with the witness (Wells et al., 2006). The interviewer also encourages the witness to provide a narrative account of the witness event. This is followed by probing questions relating to the details the witness has provided (Wells et al., 2006). The goal of the interviewer is to interrupt as little as possible and allow the witness to dictate the subject matter, sequence of questioning, and maintain active listening.
To begin the cognitive interview, the interviewer attempts to build rapport with the witness. Building rapport allows the witness to be more at ease and it minimizes the discomfort and distress that is usually associated with sharing an intimate or fearful experience with a stranger (Wells et al., 2006). In addition, building rapport allows for increased accuracy by way of open-ended questioning. The optimal goal is to transfer complete control to the witness (Wells et al., 2006).
Identifying Criminal Suspects
Identifying a criminal suspect plays a very crucial part and, in most cases, is the most important eyewitness evidence presented at trial. This becomes true when an eyewitness makes the claim to have seen the suspect commit the criminal act (Wells et al., 2006). The identification testimony then becomes direct evidence of guilt and establishes a sense of accuracy in the grand scheme of whether the suspect committed the crime or not. Eyewitness testimony, regardless of whether the identification is direct or circumstantial, is looked upon as accurate by the observers if the eyewitness displays consistency and confidence (Wells et al., 2006).
Lineups
Lineups are the primary method for obtaining identification of criminal suspects (whether it is live or photographic) and involves placing a suspect among fillers, asking the eyewitness if he or she can identify the perpetrator (Wells et al., 2006). The two possible states of truth include the suspect is the target and the suspect is not the target. With only one suspect being involved in a lineup, the two states are equal to target-present and target-absent lineups (Wells et al., 2006). In a target-present lineup, two kinds of errors can be made. The incorrect rejection (making no identification) or the identification of a filler (Wells et al., 2006). Lineups are used in different variations whether it is simultaneous, sequential, double blind, or target removal without replacement (RWR) lineups (Wells et al., 2006).
Simultaneous and Sequential lineups
Simultaneous lineups are the traditional police lineup utilized for which all members are presented to the eyewitness at once (Wells et al., 2006). The witness chooses an individual in the lineup who they believe is the perpetrator or reject the identification of any of the individuals in the lineup if no one is deemed in their eyes to be the suspect in question (Wells et al., 2006). In contrast, the sequential lineup presents the lineup members to the eyewitness one at a time. The witness has the opportunity to make a decision on the individual presented in front of them before the next member in the lineup is presented if needed (Wells et al., 2006). The number of members who will appear is not disclosed to the witness. The idea behind the sequential lineup is to prevent the witness from relying on relative judgment and using the process of elimination (Wells et al., 2006). Despite a lower mistaken identification rate for sequential lineups, it also yields a lower reduction in accuracy in regards to identification (Wells et al., 2006).
Double-Blind Lineups
A detective who is aware of the person of interest usually conducts a police lineup. This person is known as the suspect. All remaining members of the lineup are considered fillers. Experiments have indicated an increase in the eyewitness identifying the suspect when the lineup is administered by an individual who believes that a particular lineup member is the suspect (Wells et al., 2006). A double-blind lineup is when the administer is not aware of which lineup member is the suspect and which members are fillers (Wells et al., 2006).
Removal-without-replacement (RWR)
A removal-without-replacement (RWR) lineup is when an eyewitness views either a six-person or five-person lineup in which one member of the lineup is removed and not replaced (Wells et al., 2006). The eyewitness is notified prior to the lineup that the target might not be present. A removal-without-replacement lineup is most effective when the memory of the witness appears to be weak (Wells et al., 2006).
Composites
The utilization of sketch artists or composite faces takes place when there is no clear suspect. The original system, Identi-Kit used line drawings of facial features on transparencies to create a composite (Wells et al., 2006). Currently, composite production systems create faces by selecting features, which will then be combined into a face (Wells et al., 2006).
Reference
Wells, G. L., Memon, A., & Penrod, S. (2006). Eyewitness evidence: Improving its probative value. Psychological Science in the Public Interest, 7(2), 45-75.