By Daniel Becerril
MONTERREY, Mexico (Reuters) - In the courtyard of a jail that was shuttered last week, a man wearing a surgical mask and gloves used an underground scanner to search the earth for hidden graves in what was for decades one of Mexico's most violent prisons.
The Topo Chico prison closed last week after a 76-year history that saw riots, fires and bloody internal quarrels. A doctor who was in custody decades ago inspired one of the lead characters in the 1991 movie "The Silence of the Lambs."
Authorities have vowed to continue "until we finish combing the whole area as it should be," Aldo Fasci, security minister for Nuevo Leon state told reporters. "The hardest part ... is underground, unfortunately, but it must be done."
Dozens of police and military officers with dogs continued to search on Tuesday. Inmates' relatives said they had disappeared at the site.
The prison is best known for a massacre in 2016 that left 49 dead and a dozen injured as warring gangs, the Cartel del Golfo and Los Zetas, fought for control of the site.
Although Fasci said there were no signs of clandestine graves in the prison, policemen nonetheless extracted soil as dozens of dogs, mostly Belgian Shepherds, sniffed around. The government has said it plans to eventually convert the site into a public park and a museum to dissuade youth from a life of crime.
The reports of clandestine graves "are legends, but we have to confirm them or rule them out," Fasci said.
(Reporting by Daniel Becerril, Writing by Ana Isabel Martinez; editing by Grant McCool)