Mexican prosecutors are reviewing possible house-arrest sites for Ernesto Fonseca Carrillo, an 85-year-old drug lord with 10 years left to serve for the 1985 slaying of Drug Enforcement Administration agent Enrique "Kiki" Camarena.

The United States was outraged two years ago when drug lord Rafael Caro Quintero's conviction in the notorious killing was overturned on procedural grounds. Another 'grandfather' of the drug trade is Miguel Angel Felix Gallardo, who remains in prison.

A federal official who was not authorized to be quoted by name said Friday that a court ruled in January that Fonseca Carrillo was eligible for a type of house arrest offered to elderly or infirm prisoners.

The government is reviewing defense proposals for the site, where Fonseca Carrillo would be guarded by police or prison employees.