Forbes reports the story thus

Justice Department No. 2 Makes Ominous Comments On Marijuana Legalization

https://www.forbes.com/sites/tomangell/2017/09/14/justice-department-no-2-weighs-in-on-marijuana-legalization/#78153d642cfb

“We are reviewing that policy. We haven’t changed it, but we are reviewing it. We’re looking at the states that have legalized or decriminalized marijuana, trying to evaluate what the impact is,” Deputy Attorney General Rod Rosenstein said in an appearance at the conservative Heritage Foundation.

“And I think there is some pretty significant evidence that marijuana turns out to be more harmful than a lot of people anticipated, and it’s more difficult to regulate than I think was contemplated ideally by some of those states,” he said.