The new guidelines order federal prosecutors to respect state-sanctioned medical marijuana use. The federal government is shifting its priorities to stopping large-scale illegal drug trafficking.
"I think that the new policy from the Obama administration is a great first step," said Don Duncan of Americans for Safe Access.
"There are still some unanswered questions that we have to deal with, and those will be questions are about people who, for instance, have to deal with facing charges, will they be able to make an affirmative defense in federal court?" Duncan added.
"If you are selling marijuana illegally, the law says that if you sell marijuana, it's illegal," said L.A. City Attorney Carmne Trutanich.
Trutanich says he is in favor of legal medical marijuana, but there is concern that in Los Angeles County, there are more than 800 dispensaries.
"What we have now are the proliferation of stores selling marijuana as if they were pharmacies. There is no control over the product they are selling," Trutanich added.
L.A. County District Attorney Steve Cooley released a statement Monday regarding the new policy which read: "The Attorney General's announcement recognizes that those dispensaries operating in violation of state law are subject to prosecution by t he state and federal governments."
However, Cooley just recently said that he doesn't believe there are any legal dispensaries in Los Angeles.
"He is wrong. He is basing his interpretation on a faulty opinion about the law, and we're actually going to take out a temporary restraining order on him. We're going to seek a temporary restraining order on the district attorney for his statements," said James Shaw of the Union of Medical Marijuana Patients.
Also, a judge ruled Monday that the city of Los Angeles's moratorium on new medical marijuana dispensaries is invalid, and now some expect that more dispensaries will start to open up.
Eyewitness News reporters Carlos Granda and Leslie Miller contributed to this report.