At the bottom of the grave were the jumbled bones of two skeletons, which Martinez had cleared away with a bricklayer's spatula and a brush. She gently lifted the bones and examined them for signs of violence and age.
Identification would be difficult because the heads and extremities of both bodies had been cut off, a common practice of paramilitary executioners, and no documents were recovered. But Martinez collected strands of clothing, a plastic cellphone holder and sunglasses, clues that could lead to an identification by the victims' families.
"The guerrillas have a different modus operandi," Martinez said. "They don't dismember people."
The graves had been pointed out by Adan Rojas, 36, a top lieutenant of notorious commander Rodrigo Tovar, or "Jorge 40," supreme commander of the so-called Northern Block paramilitary forces. Tovar and 13 other leaders were extradited to the United States in May on terrorism and drug-trafficking charges.
Under heavy armed guard, Rojas had accompanied Martinez and the others up winding gravel roads and through mountain ravines to the remote grave sites. He was there to comply with the demobilization law, which promised paramilitary fighters light sentences in exchange for confessions and help in locating their victims.
"I participated in 100 killings," Rojas said calmly in a brief interview 30 yards from where Martinez was working, his prison guards hovering nearby.
"It was war," he said, adding that he and others under Tovar's command were defending themselves from leftist insurgents. Prosecutors believe Tovar controlled massive drug-trafficking and extortion rackets.
Because of the backlog, Martinez's team works quickly, taking only 2 1/2 hours on average to dig up each grave, gather clues and then bag and number all human remains before moving on to the next site. Crime scene investigators in the U.S. might spend days at a similar scene, said her boss, prosecutor Omar Cardoso.
The pace of work has picked up over the last year and a half with the increasing number of confessions by paramilitary leaders such as Rojas.
Victims' families, after having been cowed for years, are slowly coming forward to claim the remains of loved ones, prompted by the recoveries by forensics teams, government encouragement and a DNA program in which the country spends an average $1,500 per case to match genetic evidence with family samples.
