The United States constitution guarantees every person trial by jury if the amount in controversy exceeds twenty dollars. This right applies to any criminal issue, down to a simple parking ticket. One need not demand a jury trial, but if one wishes a bench trial, he must inform the court that he wishes to waive his right to a jury trial.
Ones peers are ones social equals. It is commonly accepted that peers are the residents of the community in which one resides. There is the possibility of variance dependent upon the composition of the jury; however this is an imperfection that apparently has no solution. Both prosecutor and defendant are entitled to strike from the jury a limited number of persons without explanation (provided the juror is not dismissed because of his/her race) and an unlimited number if he can state a legitimate cause to do so.
The O.J. Simpson trial continues to be controversial; however it is both unfair and unwise to blame this on the jury system. The trial was moved to prevent unfair publicity, and both prosecutor and defense had some role in who was seated on the jury; therefore the effect of moving the trial was most likely minimal. As to whether a bench trial would have produced different results, one can only guess. However, having spent twenty years practicing law, I can tell you that any person who chooses a bench trial over a jury trial should do so with an abundance of caution.