The American legal system has used plea bargaining for well over a hundred years, and one of the primary justifications for the use of plea bargaining is the principle of judicial economy. Judicial economy simply means that one goal of the judicial system is to conclude cases in an efficient and speedy manner. Without plea bargaining, it's widely believed that there would be an explosion of cases which in turn would overtax and disrupt the current legal system.
The primary benefit of plea bargains to a judge is that they reduce their already crowded calendar of court cases. It takes months, if not years, to get a trial date, so judges are always eager to have parties settle the matter between themselves and keep the dispute out of the court room.
Many judges also see plea bargains as advantageous because they represent an agreement or bargain between the parties, which makes compliance and adherence to the agreement more likely. This, in turn, reduces potential disputes the parties will have in the future and will hopefully prevent parties from having to come back to court.
Finally, most judges are keenly aware that many state's prisons are also overburdened. Many judges see plea bargains as an effective way to deal with less heinous criminals and reserve limited prison space for serious threats to the community.
Prosecutors have their own calendars to worry about, and for the same reason as judges, prefer to keep the calendar as free as possible. Especially in offices where funding and resources are a major issue, prosecutors are open to negotiating a plea agreement rather than spend the time, money and resources on a full trial.
Similarly, many prosecutors like plea bargains because they give the prosecutor flexibility and allow them to "screen out" smaller criminal offenses. By screening out lesser offenses, a prosecutor can bring the full power of their office to focus on serious criminal offenses. For instance, many prosecutors would rather focus their time on a high-profile murder case than a minor drug possession case, both for political and practical reasons.
As any good attorney knows, if it matters to the judge, it had better matter to you. Prosecutors know that judges want to keep trials moving and not fill up the court calendar, and prosecutors want to stay in good favor with the judge. Accordingly, prosecutors always want to appear ready to solve the dispute outside of the court room in order to avoid the wrath of an overworked judge.
Plea bargains also result in convictions, and prosecutors are measured by their conviction rate. Most prosecutors would rather spend a week negotiating a plea for a lesser conviction than spend a year to achieve a greater conviction. They can still tout their conviction rate, and claim to be "tough on crime", while doing it in a much more efficient manner.
Finally, any experienced prosecutor knows how much of a gamble a trial really is. Plea agreements, however, are a sure thing. Even if the case seems reasonably air-tight, most prosecutors would rather have a certain conviction over an uncertain trial. All it can take is one juror to wreak havoc on months or years of effort. Accordingly, even if a prosecutor is confident, there is a good chance that he or she would rather settle the case by a plea agreement than roll the dice in the courtroom.
While plea bargaining may have benefits for judges and prosecutors, ultimately, the decision rests in your hands. If you're facing criminal charges, you need honest and complete information about the consequences of accepting or not accepting a plea deal. That's where it's beneficial to consult with a skilled criminal defense attorney who will be the only person with a duty to zealously defend your interests.
