Purdue University Global
Eyewitness accounts, when weighed against other possible evidence, are not the preferred type of evidence by which a prosecutor would like to go to trial with: They are considered the least reliable, and indeed, DNA evidence, financial and personal records such as phone and text messages, security images, fingerprint evidence and audio evidence which is the preferred types of evidence by which a prosecutor prefers to seek a conviction.
That being said, eyewitness accounts have been known to be a leading cause of false imprisonment. There could be several reasons behind this, such as; Deliberately choosing a ‘suspect’ based on a grudge, pressure from law enforcement officials to choose a suspect, gut instincts that they chose the right person, choosing a suspect based upon physical similarities to the true suspect, and even faulty memories.
What is a lineup? It is a grouping of possible suspects presented in a line in which all share similar characteristics. This can be done in a physical lineup or within a photo array which is shown to the victim. In the physical lineup, the suspects are posed behind a one-way mirror, allowing for the victims and witnesses to view the suspects without the fear of being seen by the possible suspects. The witnesses can point out to each suspect to have them step forward and to even have them speak, if needed, similar phrases that the witness had heard the suspect speak in order to hear if the voice is similar, as well .
The photo array is when investigators collect photos of individuals bearing physical similarities to the eyewitness descriptions that are then shown to witnesses to try to garner an identification. There are two types of photo lineups- the simultaneous and the sequential lineup. The simultaneous lineup is when the photo array is presented all at once to the witness, allowing them to view the photos side-by-side. This type of lineup relies on relative judgement. The sequential lineup relies on absolute judgement by the witnesses to try to identify a suspect. The photos are presented to the witness one-by-one, thus there is no ability to do a side-by-side comparison .
There are two variables that should be considered when eyewitness identification of a suspect is being conducted. These variables are the system and the estimator variables. System variables are those which can be controlled by the system, such as types of suspects presented in a lineup, what is said to the witness during the viewing of the lineup, and cues given by law enforcement if they ‘know’ the suspect is in the lineup. Estimator variables are those that cannot be controlled by the system, that is to say, variables that are key to the witness. Examples of estimator variables include: The length of time between the crime committed and the lineup, the time the witness had to view the suspect during the commission of the crime and the distance between the witness and the suspect at the time of the crime .
System variables can be considered and controlled through methods such as the sequential photo array, finding good ‘fillers’ for their lineup, recording the witnesses certainty at the time of identification, and conducting the identification through blind administration, which is when the individual conducting the lineup is unfamiliar with the case. Following such procedures can help reduce the chances of a false conviction and imprisonment .
Estimator variables can be mitigated by conducting the lineup soon after the crime has been committed so that the details are fresh in the witnesses mind, gaining assurance that the witness was relatively close to the suspect and had a good view of the person in question, and recording the witnesses’ certainty within the case files at the time of the identification. As stated in the above paragraph, following such procedures can help to reduce the chances of a false conviction and imprisonment .
There are ethical issues that must be considered when law enforcement personnel are dealing with eyewitness accounts and identifying a suspect. One such ethical consideration for law enforcement officers would be that of influencing the witness, either inadvertently or blatantly: This can be done via unconscious cues such as tensions, pauses during the procedure, or even outright pressuring the witness to choose a suspect by saying that the suspect is present in the lineup. Such actions taint the identification and can lead to wrongful conviction and imprisonment. This can be mitigated by utilizing a ‘blind’ administrator to conduct the lineup .
Another ethical concern would be that of police pressure to evoke a confession from the ‘suspect’. The police can be under a lot of pressure to solve the crime from the public and media, and this pressure can translate into their interactions with suspects. There is also the possibility that the interrogator may be biased against the individual or hold a grudge against them, thus leading to their pressure against the suspect to produce a confession .
There are many factors to be considered when conducting a lineup and the possible convictions that can follow. As discussed earlier, eyewitness testimony is considered the least reliable piece of evidence in a criminal case and should be viewed with a healthy amount of skepticism. The possibility of false convictions and imprisonment should be mitigated by following proper procedures, as well as avoiding placing pressure on the witness to produce an identification if they are unsure of the truth of the matter. Everything should be recorded in order to avoid situations that could lead to a case being overturned due to police conduct and/or technicalities, as well as to prevent false convictions and imprisonment.