Lineups are considered to be "critical stage" and the prosecution may not admit into evidence in-court identification of defendants based on out-of-court lineups or show-ups if they were obtained without the presence of defendant's counsel. Courts have found that a defendant's counsel is necessary at a lineup because the lineup stage is filled with much potential for both intentional and unintentional errors. Without the defendant's attorney present at the lineup, these errors may not be discovered and remedied prior to trial.

This rule does not apply to other methods of obtaining identification and other evidentiary material relating to the defendant, including the following:

• blood samples
• DNA samples
• handwriting samples
• vocal samples

In these cases, there is far less chance that the absence of counsel at the time the evidence is obtained from the defendant might prevent the defendant from getting a fair trial.

The Sixth Amendment does not guarantee the presence of the defendant's counsel at a pretrial proceeding unless the physical presence of the defendant is involved. Furthermore, the defendant's presence must be required at a trial-like confrontation at which the defendant requires the advice and assistance of counsel.