That's an interesting question that I don't think I'm equipped to fully answer.
Every country has its own laws, and I am not an expert in the laws of every country. Many countries have no plea bargaining at all for their domestic procedures. I think Colombia might be one of them. Plea bargaining is more or less a North American institution. But regardless, as I understand it, the only way you could serve a sentence in Canada for something you've done in another country is through the exchange of prisoners treaties. If a person is convicted in a foreign country and they're a Canadian citizen, they can apply to serve their sentence in Canada, if there's a relevant treaty in place. That's the only way I'm aware of that somebody serving a sentence in another country could come to Canada.
As for cooperating with law enforcement, that's a matter for my friends at the RCMP to answer. I suspect, like me, they would find it very difficult to answer that question. It would be very fact based.