The number of people on a jury depends on what kind of case is at issue. Civil cases require six jurors while criminal trials require between six and twelve, depending on the nature of the crime. In all cases, the selection of a jury is one of the first things done in courtroom. The jury is selected by the attorneys on both sides after each are allowed to question prospective the jurors.
Some jurors find it odd, even insulting, that before the trial begins, attorneys from both sides will question potential jurors about a wide range of topics to find jurors who likely will be impartial. It should be obvious–for example– that an insurance agent as a juror may have trouble being fair to a company he or his family works for.
There are many other, backgrounds and beliefs that would make it impossible for a juror to be fair in one trial while he or she may be the most fair in another type of case.
The jury selection process by which the final panel of jurors is selected is not meant, by either side, to offend anyone. That is the last thing wanted by either. However, there is a legitimate period of questioning and answering to determine if in that particular case a juror may or may not be able to render an independent verdict.
Once the jury of six or twelve has been selected, the case then proceeds to trial.