It's not the RCMP but Crown lawyers that decide how many charges and how a case will proceed in Court.  G&M reported earlier that RCMP recommended about 10 charges but the Crown decided to go with more than 30.  The Crown, if not satisfied with the evidence in the investigation, can direct the RCMP to interview more witnesses or investigate further before proceeding to trial.  I believe that the RCMP only investigates but lawyers determine strategy and present at trial.