From the outside, Robert’s Drug Store seemed like an ordinary mom-and-pop pharmacy, conveniently located on the first floor of the Stephen P. Clark Government Center, the 28-story heart of Miami-Dade County government.

But federal authorities say the pharmacy, steps from a heavily used Metromover stop, was actually operating as a pill mill illegally trafficking in painkillers, part of a wave of rogue pharmacies that have become the new front line in the continuing war on prescription drug abuse in Florida.

The pharmacy’s owner, Aiman Izzedin Aryan, has had his pharmacy permit suspended by state regulators, and the store, while open, no longer fills prescriptions for oxycodone — or any other drug.

“This is an epidemic, a public health crisis that has killed thousands in Florida. Our strategy is to attack the problem from all angles, from all the sources of oxycodone,’’ said U.S. Attorney Wifredo Ferrer. “This is all a very tight web of doctors working with clinics and using pharmacies to make the business look legitimate and everybody is making money. We are seeing more and more pharmacies involved.’’

In the constant battle to crack down on the newest method of peddling prescription drugs to the addicts who crave them, authorities have recently broadened their strategy to focus on pharmacies in addition to pain clinics and doctors. Ferrer says criminal investigations will at least slow the epidemic, especially in tandem with rigorous new anti-pill mill legislation that went into effect in Florida in July. Under the law, the state Department of Health will play a role in determining the appropriate monthly dosage limit that pharmacies can dispense. The permit process to open new pharmacies in the state has also been made far stricter.

At least one major pharmacy has recently stopped filling the prescriptions of certain drugs by a small number of doctors in Florida.

“In the beginning of our takedowns, we were seeing more of the pain clinic owners but as the fraud has evolved so have the kinds of businesses involved,’’ Ferrer said. “This is at the top of my agenda and we are hoping the new law and regulations will help stem the problem.’’

In the past several years, as Florida became known as the nation’s painkiller capital , local, state and federal agencies concentrated initially on the growing number of storefront pain clinics — at one point there were 150 in Broward County alone — that liberally doled out prescriptions for highly addictive medicines with little or no medical cause. But that didn’t stop the vast river of pills flowing through the state, attracting drug tourists from as far away as Kentucky, Tennessee, Turkey and Mexico, and pushing overdose rates to new heights, so authorities were forced to widen their probes.

Doctors working with the clinics who wrote the tainted prescriptions came under scrutiny along with healthcare billing fraud schemes involving the clinics and, now, the complicit pharmacies that fill the prescriptions.

Part of the strategy: Use criminal laws to charge unscrupulous doctors with homicide and pill mills and pharmacies as organized criminal enterprises.

Since the summer, federal investigations have uncovered drug trafficking rings involving oxycodone and seven pharmacies in Broward and Miami-Dade, the stores collectively distributing millions of pills. One Plantation pharmacy named in an indictment filled 72 prescriptions for painkillers in one day for a total of 13,387 pills and $30,532.