I wouldn't say that legalizing marijuana would reduce the amount of work and effort that police agencies put into organized crime. I'll use the analogy that tobacco is legal, yet tobacco is a huge contraband item that organized crime groups manipulate to generate revenue. It's not necessarily whether or not the contraband is legal or not; it's the leverage that organized crime puts against it to generate the revenues.
On October 23rd, 2009. See this statement in context.