FORENSIC PSYCHOLOGY
IMPROVING THE VALIDITY OF THE LINE-UP
Line-up refers to a criminal investigation technique in which the police arrange a number of individuals in a row before the eyewitness and ask the eyewitness to identify which (if any) of the individuals committed a crime. But this criminal investigation technique has its own flaws. Researchers have found that in most cases the eyewitness labels the innocent as a suspect. There are multiple reasons for the same.
REASONS WHY AN INNOCENT IS PICKED AS A SUSPECT
Physical Bias
The picture of the suspect in a photo line-up may be noticeably different from the others (e.g. the picture can be larger or the background may be different). And because of these differences there are chances that the witness infers the odd picture must be the suspect.
Focus on Weapons
It has been noticed that eyewitnesses commonly testify as to their focus on the perpetrator’s weapon. Though the witness can recount the exact size, color and shape of the weapon, there are chances that the witness cannot reproduce the perpetrator in his/her brain.
Suggestive Identification
There are times when the investigating officer gives subtle cues through pauses, hesitations, gestures or smiles which gives indication to the witness that he/she has chosen the wrong person as the perpetrator.
Show- Up
The investigating officer takes witness to a location in order to show him/her the suspect that has been apprehended. There are times when the eyewitness will see the suspect in handcuffs or sitting at the back of the police car. This results in an automatic assumption that the eyewitness will make and he/she will think that the officers must have additional evidence regarding this person, therefore he/she is the perpetrator.
Relative Judgement Theory
There are chances that the person in the line-up who looks most similar to the culprit will be picked up by the eyewitness as the culprit.
Trauma
It is difficult for the witness to identify the perpetrator in traumatic situations such as assault, rape, murder and robbery etc, which points towards the optimality encoding hypothesis in 'can it be affected?' section.
Human Memory
It is difficult for a person and impossible for our brain to interpret everything we see. Specific details about a stranger like his/her height, weight, age, and hair are often overlooked. So when the police asks the eyewitness to recount the specific details of a suspect, the eyewitness finds it difficult to do so as the ability to rewind a video in our brain regarding what we saw is diminished and as a result the brain fills in details one cannot recount in an effort to recreate a full picture. This ultimately results in bad eyewitness identifications.
Unconscious Transference
There are times when the eyewitness has seen the suspect before and not at the crime scene. The witness does not realise this and this confusion results in error in identification.
WAYS IN WHICH THE VALIDITY OF THE LINE-UP CAN BE IMPROVED
Attempts have been made in order to formulate procedures that would help prevent the wrong person being identified in a lineup. Following are the suggestions given by Brewer and Palmer in 2010 in order to plan a satisfactory lineup.
Only one suspect should be involved in any one line-up. The foils/stooges(persons who are known to be innocent) should be plausible based on the witness’s description. It should be kept in mind that the foils/stooges are nowhere overly similar in their appearance to the suspect.
If the eyewitness has already seen and searched through the photographs of the suspect then they should not be put through a line-up for that suspect. This can lead to biases.
Sequential line-up procedures can be used in which one individual is shown at a time to a witness, usually through the use of photographic images. It is less likely that the relative judgement theory (explained previously) will operate in a sequential line-up.
If in case the investigating officer disconfirms with the eyewitness decision in identifying the suspect then he/she should refrain himself/herself from giving any feedback. And if it’s possible then the witness can be asked to view a different line-up.
Double blind line-up refers to a line-up procedure in which both the eyewitness and the line-up administrator have no idea of who the suspect is. Therefore, A double blind line-up procedure should be put in use for the administration of the line-up/ identity parade.
Eye-witness should be told beforehand that there are chances that the culprit might be absent in the line-up or identification parade.
Once the eye-witness has identified the suspect then his/her identification decision should be recorded (preferably video-taped, suggested by Kassin in 1998) immediately together with the confidence of the decision.
Apart from these, some other steps can be taken in order to improve the validity of the line-up.
All law enforcement agencies should give their officers and agents training on vision, memory, the variables that affect them, on practices for minimizing contamination and on effective eyewitness identification protocols. Investigating officer should allow the eyewitness to come to a conclusion only when he/she has seen all the photographs. Also accuracy at identifying the suspect is better when the session stops after an identification is made.
Examples of flaws in the line-up process
Brooklyn Nine-Nine is an American police procedural comedy television series. Here is a scene from the series that depicts the flaws in the criminal investigation technique (line-up)
In the video it is clearly mentioned that the eyewitness did not see the suspect but remembered the song that he was singing. The problem lies in the fact that when the investigating officer asked the fillers/foils/stooges to sing the exact song, he started to sing along and got so engrossed in this whole process that he forgot about his main job. Along with this, the eyewitness identifies the filler number 5 as the suspect. This could be because he was singing passionately as compared to others. Moreover, there is actually no way to be sure that number 5 is in fact the offender since the witness only heard the voice of the perpetrator from the bathroom. Hence, we can say that this lineup or in fact testimony is not at all accurate.
Steps taken to improve the validity of the line-up
Below is the the video that clearly summarizes the suggestions mentioned above regarding how the validity of the line-up can be improved.
References
https://californiainnocenceproject.org/issues-we-face/eyewitness-identification/
https://www.nap.edu/read/18891/chapter/8#107
Howitt, D. (2018). Introduction to Forensic and Criminal Psychology (6th ed.). Pearson.