If the complaining witness wants to “drop all charges”, will the case be dismissed?

Not necessarily. There are many reasons why the alleged victim or reporting party may have a change of heart. It may be that the report of crime may have been false or inaccurate. It may also be that the person is scared to proceed with a prosecution because of threats. The police and the prosecutor’s office are aware of all the reasons, and do not just “drop charges.” They attempt to re-interview the reporting party to understand the reason behind the change of heart.