What guidelines were stated in the neil v biggers case?

which govern the admissibility of evidence in civil actions and criminal proceedings, impose requirements that must be met before the testimony of an eyewitness can be presented during trial. For example, an eyewitness must be competent (legally fit) and qualified to testify in court. A witness who was intoxicated or insane at the time the controverted event occurred will be prevented from testifying, regardless of whether he or she was the only eyewitness to the occurrence.