Article Photos: Marijuana legalization raises safety questions 3/6

In this photo taken on Friday, Jan. 4, 2013, a lab technician prepares a sample of marijuana for testing at CannLabs in Denver. Tiny bits of marijuana are chopped even finer and put through chemical analysis in a tiny Denver laboratory that is on the leading edge of what could be a whole new endeavor for states that have legalized pot: marijuana product safety.(AP Photo/Ed Andrieski)