"What measurements will the department use to assess the damage done in Colorado, Washington and other states that legalize marijuana?" said the letter from Project Safe Approaches to Marijuana, Drug Free America Foundation, National Association of Drug Court Professionals and other groups.
The DOJ announced last week that it would not sue Washington or Colorado over plans to tax and regulate pot sales for adults as long as the states adhere to the federal priorities that include preventing drugged driving and keeping marijuana away from kids and off the black market.
The Justice Department noted in its memo that strong state regulatory systems could actually enhance federal law enforcement goals by keeping marijuana profits from cartels.
Washington's recreational marijuana law devotes some of its tax revenue to teen prevention and to public health education, and it includes restrictions on marijuana advertising.
Alison Holcomb, the author of Washington's marijuana initiative and drug policy director at the American Civil Liberties Union of Washington, encouraged the groups to review the evaluation requirements built into Initiative 502.
Washington's law requires periodic evaluation of harm resulting from use as well as reviews of public health, public safety, economic and social justice issues, she said.
"The truth is that without this evaluation and comparison, these groups have no way of knowing whether regulated legalization is a mistake," Holcomb said. "What they do know or should know if they're taking a fair look at the big picture is that the status quo is doing far more harm than good."