Under what conditions can a defendant challenge pre-trial identification techniques on due process grounds?

A defendant can challenge pre-trial identification techniques on due process grounds when the identification procedure is unnecessarily suggestive and creates a substantial likelihood of misidentification. This standard stems from the recognition that pre-trial identifications need to be conducted in a manner that minimizes the risk of errors, ensuring that the accused's right to a fair trial is upheld.

Identification techniques can be deemed unnecessarily suggestive if they highlight the suspect in a way that can influence the eyewitness's perception. For instance, if a witness is presented with a lineup that effectively points to one individual among others, this could be considered unnecessarily suggestive. If such suggestiveness is present and there is also a substantial likelihood that the eyewitness could misidentify the suspect, then the identification can be ruled inadmissible in court.

This two-fold requirement is critical because it ensures that due process rights are protected. Simply being suggestive is not enough; without the element of substantial likelihood of misidentification, the challenge may not hold up in court. The requirement reinforces the integrity of the judicial process and the reliability of eyewitness testimony, which can be incredibly influential in criminal cases.