Arizona officials used a bingo-style machine with sets of numbered air-blown balls Tuesday as they picked winners from among more than 400 applicants for certificates to run 97 medical marijuana dispensaries around the state.

The lottery is a key step toward implementing the voter-created health program. But State Department of Health Services Director Will Humble says the process of opening the dispensaries is still ongoing.

"Nothing that you saw today authorizes anybody to operate a dispensary. It's an invitation, once they get their agent card, to proceed to the next step, which is to get their approval to operate. In order to get an approval to operate from us, they're going to have to demonstrate everything that they put in their business plan is in place," Humble said.

Earlier this week, Arizona Attorney General Tom Horne issued a non-binding opinion saying that, once implemented, the state's program will violate federal law.