Update 12/19: I interviewed the owner, Amir Ousman, about the allegations. "We don't sell that here," he said. Read the follow-up article.
It appears that Petworth Market convenience store (3715 Georgia Avenue NW) may be up to the same thing as the Riyad inconvenience store. The Riyad had been selling illegal synthetic drugs until it voluntarily shut down (after being raided by MPD, vocal community action and involvement by the DC Office of the Attorney General).
According to MPD, the Petworth Market (found online as "Afran Inc") "has not been a very good neighbor." This location was busted by an undercover narcotics officer in the past for selling K2 (one variant of a synthetic drug). The penalties for selling synthetics wasn't as severe at that time; now, however, is a different story.
MPD has the ability to close a business for 48 hours if they know it is selling synthetic drugs. At that point the case can be given over to the Office of the Attorney General to sue to close the establishment, or criminal charges can be brought by the US Attorney.
In this recent incident, DC Tax & Revenue was conducting an inspection at the Petworth Market when they found packages that appeared to be either synthetic drugs or illegal marijuana. The case was turned over to MPD who is currently investigating. If the packages turn out to be an illegal substance, criminal charges can be brought and they can be temporarily shut down.
I'm all for small convenience stores and local-owned business, but no business should be selling illegal substances. If this stuff DC Tax found wasn't illegal, I hope Afran Inc just cleans up their tax issues. If it is illegal, I hope DC treats the Petworth Market just as they treated Riyad: mediates the situation with the owner and closes down a bad operator in the neighborhood.