Sometimes we do not get the information that we really need because we fail to ask the correct question. Therefore, you want to be very careful here and make sure you are asking the right questions that will provide you with a useful and meaningful response. With that in mind, I offer you the following:
First, perhaps your primary question should be whether a knowledgeable and well prepared attorney will generally produce any better outcome in a particular case ? And the answer to that question should be obvious.
Perhaps, your second question should be whether one can be assured of knowledgeable and well prepared representation if a private attorney is retained as opposed to having a public defender appointed? And the answer to that question is....not necessarily ! Both private attorneys and public defenders vary widely in quality. There is no accurate "one size fits all" answer.
Then, perhaps your third question should be whether there are certain advantages to retaining private counsel ? Perhaps the best answer to that question, as previously mentioned, has to do with case load. By the nature of the system, public defenders are burdened with a massive caseload whereas private attorneys typically carry a much lower caseload. This generally enables the private attorney to give more time and preparation to each case, often resulting in better results, and generally resulting in better more access and availability to answer questions that invariability come up.
Then, perhaps your fourth question should be whether you have a choice ? Of course, the answer here is if you can afford to retain private counsel, you are more than likely not entitled to the services of the public defender. As was previously pointed out, they are desperately needed by those who have no choice.
Then, perhaps your fifth and final question should be whether there there is anything that you can do to increase the likelyhood and probability of getting knowledgeable and well prepared representation in a particular case. And that is where retaining private counsel comes into play. Because, when you retain a private attorney, you have a choice, that is, an opportunity to evaluate not only the quality, skill and experience of the attorney that will be providing the representation, but also the the attitude, commitment, personality and fit between the attorney and the client. And nobody needs to tell you how important those factors are to the results of a particular case.
The most important difference betweem a public defender and a private attorney is case load. The public defender is typically a dedicated, capable and experienced lawyer and probably an expert not only in state court criminal defense but in the personalities and realities of your particular courthouse. The problem is that the public defender carries a massive, often an inhuman caseload. A private attorney typically carries a much lower caseload and is able to give more time to case research, investigation and preparation and should also be available to answer questions and attend to matters on a personal level which the public defender, even with the best intentions, simply is too overburdened to do.
Will a private attorney get you a better outcome? The outcome depends above all else on the facts of the case, and the lawyer cannot make or change the facts. The retained attorney and the public defender alike have to deal with the evidence.
Private attorneys and public defenders both vary widely in quality. Try to find an attorney who enjoys a good professional reputation. A lawyer who is respected by the judge and by the prosecutor is an advantage. That respect can be earned very quickly by any lawyer who comes to court knowledgeable and well prepared. It can be lost very quickly by any lawyer who does the opposite.
If you can afford retained counsel you are not entitled to the services of the public defender, who is desperately needed by those who have no choice.
I spent almost half of my 32 year legal career as a PD. The other 18 years have been spent either in firms or in private practice, as I am in now. I don't want to jump into the debate which your questions raises.
However, I will say this: If you can afford to expend some funds, but not enough to hire private counsel, you can assist the public defender's representation by paying for some of the experts or investigation yourself. Public defender budgets are limited. For example, sometimes the person in charge of approving expenses will deem a certain expert as a great help but not vital to the defense. Resources have to be conserved to make sure there is enough for everyone. So the request for the expert is denied. That's where a family can help.
So, what I am saying is that there is a kind of middle ground if you cannot afford private counsel but can afford something and want to maximize your son's representation by the PD. Good luck.
The answer is "it depends." In SF for example we have an excellent PD office which has won many gang cases. We also have private attorneys who have done the same. I know nothing about the quality of the PD's office where you are located so I can't comment on that. What you get with a private attorney is more personal attention and more time devoted to your son's case; this does not guarantee a better outcome however. If money is an issue I would go with the PD.