When people are accused of a crime, they face the terrible possibility of going to jail. A good attorney can represent anyone committed with a crime to the best of his or her ability. They can negotiate with prosecutors and can often arrange for reduced charges or lesser sentencing.
Criminal defense lawyers do much more than simply question witnesses in court. Good defense attorneys will:
Formulate sentencing programs tailored to a client's specific needs, often helping defendants avoid future brushes with the justice system.
Provide defendants with a reality check, a knowledgeable, objective perspective on their situation and what is likely to happen should their cases go to trial. This perspective is vital for defendants trying to decide whether to accept a prosecutor's offered "plea bargain".
Are familiar with important legal rules because many criminal law rules are hidden away in court interpretations of federal and state constitutions.
Are familiar with local court customs and procedures that aren't written down anywhere (for example, a lawyer may know which prosecutor has the "real" authority to settle a case, and what kinds of arguments are likely to appeal to that prosecutor).
Understand the possible "hidden costs" of pleading
Gather information from prosecution witnesses.
Hire and manage investigators, who may be able to believably impeach (contradict) prosecution witnesses who embellish or change their stories at trial.