After a long wait, medical marijuana could start being prescribed in Maryland this year. Patients awaiting the drug welcome the roll-out, but it will present a thorny problem for employers. Under federal law, marijuana remains illegal. So what does medical marijuana mean for workplace drug-testing? We hear from Dr. Ryan Vandrey, of the Johns Hopkins University School of Medicine, who studies marijuana. He explains the science of drug-testing, and the pitfalls. Then Maryland employment lawyer Julie Janofsky joins us to discuss the legal ins and outs of workplace drug-testing now that medical marijuana has been legalized.