A jury is the ultimate fact finder in a case. They must listen to both sides of the story, weigh evidence and use common sense in reaching a verdict. The judge provides jurors with the law that applies to the facts presented in the trial, and the jury must follow those instructions in making their decision. Jurors must be open minded, and not be influenced by any preconceived notions or prejudices.
Prospective jurors are randomly selected from the community for jury duty. They fill out questionnaires that reveal their views, and are asked questions about the crime in question. They are also required to answer a series of questions about their general background and experiences. They are not allowed to communicate with the outside world while they are in the jury room. They may only discuss the case with the other members of the jury. The prosecutor or defense attorney can challenge a prospective juror, telling the judge why they think that person should not serve on the jury. The judge must then decide whether or not to accept that challenge.
Observing the panel before the judge begins to strike jurors can speed up the process, especially when prosecutors have peremptory strikes (those they can use without giving any reason). A quick read of the information cards provided to each prospective juror will provide a prosecutor with some basic opinions on who should or should not be allowed to sit on the jury. For example, a juror who has an extreme opinion about criminals or auto manufacturers will not make a good juror.