Niki Crawford, who heads the meth suppression team in Indiana, said that with shake-and-bake labs, "the odors are not as strong. And they're just so portable. We find them in backpacks and gym bags."
And inside stores: A woman was arrested inside a St. Louis County Wal-Mart earlier this year with a meth-filled soda bottle in her coat pocket.
Another reason for the rise in urban meth is a process known among law enforcement as "smurfing" —the abundance of pharmacies in cities attracts meth-makers from surrounding rural areas, who can bring in friends to help purchase pseudoephedrine pills.
"We know the fuel for domestic labs is pseudoephedrine," Farmer said. "The source for that is pharmacies and the majority of pharmacies are in urban areas."
Farmer also has seen an increase in meth activity involving inner-city Tennessee gangs, which tend to be better-organized than rural cookers when it comes to marketing and selling the drug. For the most part, the gang members work as smurfers, though Farmer worries they'll eventually become involved in the manufacture and distribution of the drug. Sometimes, gang members and meth-makers first connect while in prison.
"They see there's a market there to make money off of pseudoephedrine," Farmer said. "Pseudoephedrine has become as good as currency."
Missouri State Highway Patrol statistics are indicative of the growing urban concern: All four of the top meth counties in Missouri were in the metropolitan St. Louis area — Jefferson, St. Charles, St. Louis and Franklin.
Ed Begley, a St. Louis County meth detective, said the drug is attracting users from all socio-economic levels.
"Lower class all the way up to upper middle class," Begley said. "We've even had retired folks who have become addicted. It's a brutal drug."