What is the primary requirement for conducting a live lineup?

The primary requirement for conducting a live lineup is that a minimum of three non-suspect fillers must be included. This standard is in place to ensure that the lineup is fair and non-suggestive, providing a sufficient number of individuals who are not suspects to allow the witness to make an identification without undue influence. Including non-suspect fillers helps to prevent the witness from being biased toward selecting the actual suspect simply because they are more prominent in the lineup.

A lineup should present a plausible representation of individuals so that the witness can reliably distinguish between the suspect and those who are not involved in the crime. This practice is crucial in maintaining the integrity of the identification process and minimizing wrongful accusations.

While conducting a lineup at the crime scene may sometimes be beneficial for contextual reasons, it is not a mandatory requirement. Furthermore, the suspect being the only person present would not fulfill the purpose of a lineup, which is to give the witness options and avoid suggestion. Lastly, while it is important that the witness is not aware of the suspect's identity to prevent bias, the inclusion of fillers is still the fundamental requirement for ensuring a fair lineup process.