If you read a Riverdale blog one day about the Canadian legal system and how cool it would be to be an RCMP officer and wanted to move to Canada in order to practice your trade here you're going to need to learn a whole new legal system. It's not as simple as already being a lawyer in another country, hopping out of an Oakville airport taxi and into a Canadian court to defend a client or prosecute a case. Same goes if you're a police officer from a different country.
Laws differ all over the world. Each state in the USA has their own legal system. Every province differs in some way in Canada. Then compare both countries and you will find laws that are completely foreign to each other. Same goes for other countries such as England, Australia or Italy. Everywhere you go there are different sets of laws. Different rules to follow. You easily could have two very similar cell phone audit cases tried in different countries end up with conflicting results. Every country is free to reign in whatever way they want.
It's the same for other professions. For instance, an Ajax real estate agent, no matter how qualified they are, could not move to Jacksonville, Florida and sell houses there without getting their Florida real estate licence first. It doesn't matter how respected of a lawyer or police officer you were in the previous country you lived in. If you want to work in Canada in your respected field you need to learn the Canadian legal system.
Canadian laws are different from American laws or Indian laws, or whatever country you moved from. You have to brush up on Canadian laws if you want to practice law in Canada or become a Canadian police officer. It's for your own good really. It also protects the integrity of the legal system. As well as making sure every person being tried or represented in a court of law in Canada is being represented by a fair and competent attorney.
If you were a real estate lawyer in Nevada and moved to Alberta you wouldn't know the first thing about how to close a real estate deal in that particular province. Or if you dealt with corporate law you wouldn't know the intricate details about Edmonton foreclosures. Something that might have been legal in your old hometown could be illegal in Canada. Or vice versa. You wouldn't know if you just started practicing law in Canada. Same goes for police officers. Something that might have seemed like a routine arrest in Virginia could be completely okay by Canadian legal standards. That's the main reason why you need to brush up on Canadian laws and know the Canadian legal system.