Assistant manager Dunn Ericson refills a jar of medical marijuana at the River Rock Medical Marijuana Center in Denver, Colorado, on May 16, 2013. (Anthony Souffle/Chicago Tribune/MCT)
Assistant manager Dunn Ericson refills a jar of medical marijuana at the River Rock Medical Marijuana Center in Denver, Colorado, on May 16, 2013. (Anthony Souffle/Chicago Tribune/MCT) Chicago Tribune/MCT
Assistant manager Dunn Ericson refills a jar of medical marijuana at the River Rock Medical Marijuana Center in Denver, Colorado, on May 16, 2013. (Anthony Souffle/Chicago Tribune/MCT) Chicago Tribune/MCT