What is required for a valid line-up procedure?

A valid line-up procedure requires having at least three fillers who are not suspects. This is essential to ensure that the line-up is fair and does not lead to misidentification. Fillers serve as distractions, helping to create a more balanced array of individuals for the witness to observe. Having these non-suspects increases the reliability of the identification process, as it prevents the line-up from being too suggestive or biased towards the actual suspect. It provides multiple potential choices, which is critical for minimizing the risk of misidentification and enhancing the integrity of the witness's recall.

The presence of a sufficient number of fillers, along with careful selection that matches the characteristics of the suspect but are not known to the witness, is a fundamental principle in conducting an effective line-up. This protocol supports the goal of ensuring that witnesses can make their identifications based on a legitimate assessment of all individuals presented, rather than being led or influenced by the presence of the suspect alone.