When a prosecutor looks at your case for the first time, he or she has a great deal of discretion. The prosecutor can file the same charge for which you were arrested, can amend the charge to a greater or lesser offense, or can decide not to proceed on the case all together.
When the prosecutor receives the file, it contains affidavits and reports from law enforcement, who have been trained to investigate, interrogate, and build a case against you. The prosecutor likely does not have the same information from your point of view and may not have any of the evidence in your favor, or statements from witnesses who will ultimately testify for you at trial.
Providing this information to the prosecutor and ultimately presenting it to a jury is within the purview of your attorney. The jury has the ultimate discretion.