Investigation
Kinds of crime, and how each is worked
Why a burglary, a fraud and a homicide are investigated differently, and what stays the same in all three.
Principles from published manuals, not procedure. What has to be done at a scene is set by the law of the country you are standing in and by the orders of the service you belong to; where those differ from this, they govern.
Lessons
This material is education, not certification, and it does not replace accredited professional or medical training. It describes how the association works; it is not legal advice and confers no powers.