Who is Rial Nevas from Forward the Foundation and what is their importance?

Rial Nevas is a smart-alecky young man whom Hari Seldon reprimands for littering, Nevas claims to be an eyewitness to Hari's and Stettin Palver's unprovoked attack on three young people. As he testifies at the trial, Nevas feels his throat tighten as he lies. Finding himself stared at by Wanda Seldon and Stettin Palver, Nevas breaks down and tearfully confesses the truth, resulting in an acquittal.