The US Justice Department won't be challenging state laws that permit the medical and recreational use of marijuana, it was announced Thursday. Attorney General Eric Holder revealed the news during a conference call with the governors of Colorado and Washington — both of which allow the drug to be used recreationally by adults. Simultaneously, in a memo sent to all US Attorneys, the DoJ outlined eight new "enforcement areas" around which attorneys will focus their prosecution efforts moving forward. These guidelines aim to prevent the distribution of marijuana to minors, curtail driving under the influence, stop marijuana from being diverted to states where it's illegal, and keep sales revenue out of the pockets of criminals.

Marijuana remains illegal under the Controlled Substances Act, granting the Justice Department a path to intervene if it finds numerous violations in the legalized states. For Colorado and Washington in particular (where production, distribution, and sale are all authorized) the DoJ expects to see strict regulations that directly address the eight focus areas. "These schemes must be tough in practice, not just on paper, and include strong, state-based enforcement efforts, backed by adequate funding," reads today's statement from the Justice Department. The DoJ warns that "if any of the stated harms do materialize," it may seek to challenge the laws after all.