Otherwise you are likely to end up like the three bodies - handcuffed, blindfolded, strangled and burnt - found inside oil drums on the Mexico City to Acapulco motorway last weekend. Police forensic experts said yesterday at least one of the men was a plastic surgeon believed to have operated on cocaine baron Amado Carrillo Fentes last 3 July. The other two may have been assistants to the surgeon, 37-year-old Jaime Godoy Singh, the experts said.
Carrillo, 42, died in a Mexico City clinic the following day, 4 July, apparently as the result of the anaesthetic or sleeping pills he had been given. The fact that he died on the Fourth of July - US Independence Day - raised speculation that US Drug Enforcement Administration (DEA) agents had reached his doctors and persuaded them to kill him. The DEA flatly denied any involvement.
Whether or not Godoy or his assistants deliberately killed Carrillo, both Mexican and US anti-narcotics agents knew the doctors were in big trouble. None of them ever reappeared at their homes.
Then, on Sunday, police made the gruesome discovery by the side of the motorway: three oil drums, partly filled with cement, each with a body stuffed inside. Each body appeared to have been strangled with a cable and set fire to while handcuffed and blindfolded.
Asked to identify his son's body from a photograph, Godoy's father became sick. The surgeon's brother later identified the body because of a plastic jaw prosthesis and matching dental records.
Carrillo, from the northern Mexican state of Sinaloa, was known as "The Lord of the Skies" because he controlled air routes carrying Colombian cocaine via Mexico to the US. Heading the so-called Juarez cartel, he gathered a fortune estimated at $25bn (pounds 15bn), spending much of it on paying off top police and military officers.
Earlier this year, Mexico's anti-drugs tsar, General Jesus Gutierrez Rebollo, was arrested for accepting massive bribes in return for protecting Carrillo.
There was a spate of killings in and around Ciudad Juarez, across the border from El Paso, Texas, after Carrillo's death, as rival druglords fought for his turf.