Luis Octavio López Vega, who worked for both the Mexican military and as an informant to the DEA, is now in hiding:

“The reserved, unpretentious husband and father of three has been a fugitive ever since, on the run from his native country and abandoned by his adopted home. For more than a decade, he has carried information about the inner workings of the drug war that both governments carefully kept secret.

“The United States continues to feign ignorance about his whereabouts when pressed by Mexican officials, who still ask for assistance to find him, a federal law enforcement official said.

“The cover-up was initially led by the D.E.A., whose agents did not believe the Mexican authorities had a legitimate case against their informant. Other law enforcement agencies later went along, out of fear that the D.E.A.’s relationship with Mr. López might disrupt cooperation between the two countries on more pressing matters.”