Double And Triple Lineups

In recent times, police investigations have had a rise in producing real suspects and criminals for most cases. This is due to a procedural technique called the lineup, and its various forms.

What is a Lineup?

A lineup in simple terms is a list of persons arranged by the police for identification by potential witnesses.

Taking comparisons from lineups in sports, we can as the similarity in which a lineup is a list of people brought out to be identified or known(in sports, it is to know who is present in the team for that particular game)

So also in crime, lineups are used to find out and narrow the list of suspects from a broad pool of individuals. 

Types Of Lineups 

There are 2 commonly known types of lineups.

• Simultaneous Lineups.

Simultaneous lineups are the most used type of lineups in police procedures today. 

The process involves stimulating the witness’ memory by providing images of potential suspects and requesting the witnesses to compare them to each other.

This method requires that all the images be shown at once to the witness, in contrast to the Sequential Lineup method that will be discussed later. 

Hence, the witness selects an image from the images shown, making use of a term in psychology known as a Relative Judgement. It is a method of analysing the differences in groups of aggregated data using one variable e.g. face colour, height, beard, etc.

• Sequential Lineup

Sequential lineup involves the display of potential suspect’s images to the witness, one after the other, with hopes that the witness can identify the perpetrator.

It is said to have a higher success rate than Simultaneous Lineups in providing the said perpetrator(s) of the crime committed.

Unlike the simultaneous lineups, witnesses are called to use Absolute Judgement, which is a method of psychological analysis based on judgments made about people or things that are done without the use of a specific standard of comparison.

This means that it is only the specific image of the perpetrators needed to be identified by the witness out of all the displayed images.

Forms of Lineups

Lineups are a psychological procedure 

with different forms to it. The list contains some of the forms of lineups in modern psychology

• Single Blind Lineup

A single-blind lineup is a procedure that occurs when the police present a lineup to a witness, but here the police are aware of the perpetrator involved but the witness is unaware. 

Hence, it is called a single-blind lineup because only the witness is “blind” to the identity of the perpetrator involved in the crime.

• Double-Blind Lineup

The double lineup happens when the witness is given a lineup that neither the police nor the witness is aware of the perpetrator’s identity. 

Therefore, it is termed a double lineup since both the police and the witness are ignorant of the perpetrator’s identity.

• Blank lineup

In these cases, no suspects are given to the witness to identify. It is used to get more accurate and trusted identification from witnesses that passed it. 

The Double Lineup: An In-depth View

The double-blind lineup or double lineup is by far the most effective to be used by the police in analysing suspects. 

This can be confirmed by the fact that when a single-blind lineup is used, the administrator of the lineup can unconsciously send out hints about the suspect or lack thereof thereby causing the witness to become less accurate in identifying the perpetrator. 

 Lineup Bias and Size

A well-done lineup can bring out the perpetrator of a crime committed by indicating and confirming the known suspects of the crime.

Thus, it is essential that lineups be conducted with care and no bias is found, and it has an effective lineup size.

A lineup bias occurs when a witness with deficiencies in memory( can be poor memory or as sent memory) can identify the suspect in such a way that it is more than expected of the witness 

Every lineup has a nominal size, which is the number of members present to be inspected in the lineup. The lineup then becomes unfair when it contains fillers(hints) which are not logical choices to the suspect in question as to when the witness with the defect in memory is to identify the said person. 

Two basic rules exist in lineup construction; 

• The suspect must not stand out in any way 
• Fillers to be used must be appropriate and must resemble the suspect in all ways.

Construction of Lineups

The methods of constructing a proper lineup must obey the basic rules given above: The suspect must not stand out and fillers should be effectual choice-making selections to the suspect. 

Furthermore, an eye for detail is needed to not miss the important aspects.

The administrator can start with a specific image to be presented to the witness, taking care not to aid or influence the witnesses’ ability to identify the suspect.

However, if the witness has already identified a person, a lineup that matches most of the description given should be provided and cross-referenced so that it will match that of the suspect.

Conclusion

The use of lineups(both double and triple lineups) in forensic science has pushed suspect identification into higher realms of success. It is a very helpful technique that has helped detain perpetrators of crime.