Marijuana refers to the dried leaves, flowers, stems, and seeds from the cannabis plant (shown in fig. 1), which contains the psychoactive or mind- altering chemical delta-9-tetrahydrocannabinol (THC), as well as other related compounds. Marijuana can be smoked or consumed in food or drinks, such as marijuana-infused brownies, cookies, peanut butter, candy, and soda. According to the Substance Abuse and Mental Health Services Administration, marijuana is the most widely used illicit drug in the United States. For example, according to the 2013 National Survey on Drug Use and Health, an estimated 44 percent of Americans aged 12 and older reported they had tried marijuana, and an estimated 7.6 percent of Americans aged 12 and older reported having used marijuana in the past month. Marijuana is a controlled substance under federal law and is classified in the most restrictive of categories of controlled substances by the federal government. The CSA places all federally controlled substances in one of five “schedules,” depending, among other things, on the drug’s likelihood for abuse or dependence, and whether the drug has an accepted medical use. Marijuana is classified under Schedule I, the classification reserved for drugs that have been found by the federal government to have a high potential for abuse, no currently accepted medical use in treatment in the United States, and a lack of accepted safety for use under medical supervision. In contrast, the other schedules are for drugs of varying addictive properties, but found by the federal government to have a currently accepted medical use. The CSA does not allow Schedule I drugs to be dispensed with a prescription, unlike drugs in the other schedules. Furthermore, the CSA provides federal sanctions for possession, manufacture, distribution, dispensing, or use of Schedule I substances, including marijuana, except in the context of a government- approved research project. Within DOJ, two components have primary responsibility for enforcing the CSA. DEA is the primary federal law enforcement agency responsible for conducting criminal investigations of potential violations of the CSA. U.S. Attorneys are the chief federal law enforcement officers in federal judicial districts responsible for, among other things, prosecution of criminal cases brought by the federal government and prosecution of civil cases in which the United States is a party. As part of their marijuana enforcement efforts, DEA and the U.S. Attorneys collaborate, often with state and local law enforcement, to conduct criminal investigations and prosecutions, civil and criminal forfeiture, seizures, and eradications of cannabis plants. An increasing number of states have adopted laws that legalize the use of marijuana under state law. As of June 2015, 24 states and the District of Columbia had passed legislation or voter initiatives legalizing the possession and distribution of marijuana for medical purposes under state or territorial law. In 1996, California became the first state to do so with its passage of the Compassionate Use Act, and an increasing number of states have passed ballot initiatives, propositions, or legislation under state law to legalize medical marijuana in recent years. For example, from 2007 through June 2015, 13 states and the District of Columbia passed some type of measure to legalize marijuana for medical purposes under state law. The laws these states have passed legalizing medical marijuana vary, as does the extent to which the states have established regulatory and enforcement systems to implement them. As of June 2015, 4 states and the District of Columbia had passed ballot initiatives legalizing marijuana for recreational purposes under state law. In 2012, Colorado and Washington became the first states to pass ballot initiatives legalizing the production, processing, and sale of marijuana for recreational use. In 2014, Alaska, Oregon, and the District of Columbia passed ballot initiatives legalizing marijuana for recreational use. DOJ has updated its marijuana enforcement policy in recent years in response to the rising number of states that have legalized marijuana under state law. According to a series of memorandums ODAG issued to U.S. Attorneys beginning in 2009, DOJ is committed to enforcing the CSA for marijuana regardless of state law. However, DOJ has directed its field components to focus on the efficient and rational use of its investigative and prosecutorial resources to address the most significant threats to public health and safety. According to one of the memorandums, DOJ has not historically devoted resources to prosecuting individuals whose conduct is limited to possession of small amounts of marijuana for personal use on private property. Rather, DOJ has left such lower-level or localized marijuana activity to state and local law enforcement authorities through enforcement of their own drug laws. While reiterating the department’s approach to enforcing the CSA and focusing its resources to address the greatest public health and safety threats, each of the ODAG’s memorandums provided additional clarification with respect to the conditions that may trigger federal action, including criminal investigation and prosecution. For example, in October 2009, ODAG issued guidance stating that DOJ’s investigative and prosecutorial resources should be directed towards the prosecution of significant traffickers of illegal drugs, including marijuana, and the disruption of illegal drug manufacturing and trafficking networks. Moreover, the guidance stated as a general matter, pursuing those priorities should not result in a focus of federal resources on individuals whose actions were in clear and unambiguous compliance with state laws providing for the medical use of marijuana, including individuals with cancer or other serious illnesses who use marijuana as part of a recommended treatment regimen consistent with applicable state law or caregivers who provide such individuals with marijuana in compliance with existing state law. The memorandum identified various conduct that may indicate illegal drug-trafficking activity of federal interest, while reiterating that U.S. Attorneys maintained prosecutorial discretion in addressing criminal matters within their districts. In June 2011, ODAG issued guidance stating that the 2009 memorandum was not intended to shield commercial marijuana operations from federal enforcement actions. Among other things, the guidance also stated that while DOJ’s efficient use of limited federal resources had not changed, there had been an increase in the scope of commercial cultivation, sale, distribution, and use of marijuana for purported medical purposes, and that this activity remained of federal concern. Furthermore, the guidance stated that the term medical marijuana “caregiver” referred to individuals providing care to individuals with cancer or other serious illnesses, not commercial operations cultivating, selling, or distributing marijuana. In August 2013, ODAG issued its first public guidance on marijuana enforcement since Colorado and Washington passed state ballot initiatives legalizing marijuana for recreational purposes. The guidance provided additional clarification of DOJ’s priorities and certain circumstances that may warrant DOJ to challenge a state’s implementation of its marijuana legalization program. The guidance outlined eight enforcement priorities that were particularly important to the federal government. These priorities generally focused on preventing the conduct ODAG outlined in its 2009 guidance, but with some additional activities specified. For example, the guidance included preventing the diversion of marijuana from states where it is legal under state law in some form to other states, preventing the growing of marijuana on public lands, and preventing drugged driving and the exacerbation of other adverse public health consequences associated with marijuana use. Figure 2 lists the eight marijuana enforcement priorities outlined in the August 2013 DOJ guidance. The guidance also stated that outside of these priorities, the enforcement of state law by state and local law enforcement and regulatory bodies should remain the primary means of addressing marijuana-related activity. The guidance stated that in jurisdictions that have enacted laws legalizing marijuana in some form and that have implemented strong and effective regulatory and enforcement systems to control the cultivation, distribution, sale, and possession of marijuana, conduct in compliance with those laws and regulations is less likely to threaten the federal marijuana enforcement priorities. The guidance indicated DOJ’s expectation that state systems must not only contain robust controls and procedures on paper, but must also be effective in practice, with jurisdictions providing the necessary resources and demonstrating the willingness to enforce their laws and regulations in a manner that does not undermine federal enforcement priorities. The guidance further stated that if state enforcement efforts are not sufficiently robust to protect against certain harms outlined in the guidance, the federal government may seek to challenge the state regulatory structures themselves, in addition to continuing to bring individual enforcement actions, including criminal prosecutions, focused on the enforcement priorities. Figure 3 shows a timeline with the years in which states and the District of Columbia legalized medical and recreational marijuana and the years in which DOJ issued public guidance clarifying its marijuana enforcement policy. In November 2012, Colorado and Washington passed state ballot measures that legalized recreational marijuana production, processing, sales, and possession and designated regulatory agencies to develop, implement, and enforce regulations governing the recreational marijuana industry. In 2014, these recreational marijuana regulatory agencies—the Colorado MED and the Washington State LCB—began to implement the new regulations. In general, the two state regulatory systems share similar features, including requirements for licensing, licensee and employee background checks, facility security measures, and product labeling and packaging. The following describes some of the features of the 2 states’ regulatory systems. Licensing. The Colorado MED and the Washington State LCB have established four types of recreational marijuana licenses that allow licensees (or accredited testing facilities) to conduct specific tasks, including producing, processing, or selling marijuana products, or testing marijuana products for potency and potential contaminants. Figure 4 shows the types of recreational marijuana licenses issued in Colorado and Washington. Table 1 shows the number of active recreational marijuana licenses by type as of August 2015, as reported by each of the 2 states’ recreational marijuana regulatory agencies. Background checks. Both Colorado and Washington conduct background checks to determine if applicants are eligible to obtain a license to operate a recreational marijuana facility. As part of the licensing process, both states’ regulations require applicants to submit documentation that may include biographical information, fingerprints, financial information and funding sources, and facility floor plans. The regulatory agencies review this documentation to determine whether applicants meet eligibility requirements including state residency, age, and criminal history requirements.