Buying these articles may or may not be legal, but bringing them into Canada is forbidden. Customs officers will confiscate them. As for illegal drugs, Mr. Smith mentioned Shad, a customs detector dog. On detecting illegal drugs, Shad does not bark or scratch. Customs officers are trained by Revenue Canada.
Educational qualifications are important, but even more so are personal qualities.
Trainees are taught to adapt instantly to each traveller, make quick assessments and reach immediate decisions. A confrontational attitude is self-defeating, so customs officers try to frame their questions in positive terms. While most travellers will pass through the primary inspection line without incident, a few, after claiming their baggage from the carousel, may be directed to a separate area for further questioning or examination if the first officer doubts their written declaration or spoken responses. Here, another officer takes over. He may make a cursory inspection of the traveller's luggage, or he may order a full examination of everything the person is wearing or carrying.