A recent report by The Arcview Group showed that legalized marijuana is now the fastest growing industry in the U.S., posting a whopping 74% growth rate in 2014. Despite a widespread movement to legalize marijuana for both medicinal and recreational purposes across the country, though, the industry still faces some serious challenges on the legal front that investors need to understand.

So, to give investors a deeper look at some of the more pressing legal issues, I spoke with a leading expert on medical marijuana, Aaron Lachant — an attorney with the healthcare specialist law firm Nelson Hardiman LLP.

Since 2009, Aaron and his associates have worked closely with businesses and investors in this space to ensure regulatory compliance with California state law. As such, he’s uniquely qualified to provide the investing community with an overview of the biggest opportunities — and risks — across the legalized marijuana industry going forward.

With that mind, here are the key issues this top expert thinks investors need to know before investing in marijuana stocks. [Read more at The Motley Fool]