There are different types of training. There is the training of the investigators themselves. You might think, with a police force of thousands of trained investigators, why added training would be necessary. That's because harassment of whatever type is different in its fundamental nature from criminal investigation. Harassment can of course become criminal, but RCMP members are trained in performing criminal investigations. That involves gathering evidence in preparation for lodging a criminal charge.
With respect to harassment investigations, I believe the goal should be early intervention. So the training of managers can enable the managers to spot the indicia of harassment before it becomes a serious issue. Then in terms of the investigators themselves, the initial steps should be remedial.
Only in the cases where that doesn't work would you then presumably move on to formal disciplinary hearings.