Public defenders often know the quirks, peeves and tolerances of the prosecutors and judges, and are able to use this knowledge to better know how to proceed with a case.
They also see the same police officers testifying, and know who’s likely going to be a good or bad witness for your case.
Public defenders also can rarely afford to hire investigators to collect evidence to support your case.
On the other hand, many public defenders do not have the experience that many private practice attorneys do.
Public defenders also typically work in “niched” areas of law, such as DUI or domestic violence defense.
Therefore, they tend to be up-to-date on new law and legal theories in their area of specialty.
Public defenders often “cut their teeth” on high-volume misdemeanor cases such as DWIs.