Mexican trucks already come fifty miles into the US before they have to unload their cargoes. What difference does it make whether the shipping containers are transferred to another truck or delivered by the same truck to Nashville?
After their colleagues started turning up dead, Mexico's plastic surgeons began checking their patients more carefully, refusing those who wanted full facial transformations or the camera-shy ones who didn't want their pictures taken.
Drug traffickers have turned increasingly to plastic surgery in recent years to evade the law, and have proved to be all too willing to kill the doctors who operate on them.
Sometimes doctors are killed to hide evidence, but at least one was murdered out of vanity: A trafficker didn't like the way a liposuction turned out.
At least eight doctors have turned up dead since 1994 after working on drug suspects. The number of drug lords with surgically altered features led Mexican prosecutors to issue a call earlier this year for plastic surgeons to cooperate with police and report suspicious cases.
Some doctors were apparently not aware their patients were drug traffickers; others may have done it for the money. Plastic surgeons say they watch prospective patients for warning signs: one who doesn't want a traditional "before and after" photograph taken, or requests a total change in appearance.
Most plastic surgeons try to avoid the dilemma.
"You can get out of the problem, by quoting a very high price, or telling them their skin isn't right, or that they need more tests," said plastic surgeon Hector Arambula. "Sometimes it backfires, because if you quote a high price, these people can pay it, whereas a normal patient wouldn't."
"But the amounts of money offered can be very tempting, and there is also the problem that drug traffickers can bring pressure to bear," Arambula said. "Between the police and the drug traffickers, plastic surgeons are between a rock and a hard place."
Sometimes, doctors get an offer too good to refuse.
The three plastic surgeons who operated on former drug lord Amado Carrillo Fuentes in 1997 apparently not only knew who their patient was, but were paid off to kill him with an injection of tranquilizers.
But then they were forced out of the operating room at gunpoint.
A month later, on a highway hundreds of miles away, their gagged, handcuffed and tortured bodies were found packed into oil drums with dirt and concrete.
That same year, four other doctors were slain after they operated on a drug gunman wounded in a shootout in the border city of Ciudad Juarez, across from El Paso, Texas.
Those doctors showed signs of being strangled or suffocated. At least two had bruises on their hands and knuckles, suggesting they tried to fight off their attackers.
The choice - to operate or not - has cost the life of doctors involved in operations as routine as liposuction, a common procedure that at least one overweight trafficker used to change his appearance.
Known as "The Frog" because of his jowls and double chins, drug suspect Humberto Rodriguez Banuelos was a bad bet as a patient: He once allegedly ordered the killing of a traffic cop who dared give him a ticket.
Prosecutors say he also ordered the 1994 killing of his doctor.
"He ordered the doctor killed, because he said he didn't like the way the liposuction had turned out," said Horacio Montenegro, a former associate who is himself now facing drug charges.