What is the purpose of a line-up in criminal investigations?

The purpose of a line-up in criminal investigations is specifically designed to allow witnesses to identify or eliminate a suspect from a group. This process is crucial for ensuring that the identification of a suspect is accurate and reliable. During a line-up, a witness is presented with a number of individuals, which may include the suspect, and asked to identify the person they believe to be involved in the crime. This method helps investigators determine if the witness's memory and recognition are consistent with the suspect's appearance.

Other options focus on processes that are unrelated to the primary function of a line-up. For example, finalizing an arrest pertains more to legal procedures and evidence gathering rather than the identification process. Similarly, providing legal counsel is a right of suspects and does not pertain directly to the purpose of a line-up, which is primarily focused on witness identification. Meanwhile, gathering forensic evidence involves collecting tangible materials related to a crime scene, which is separate from the witness identification process that a line-up aims to facilitate.