The stench of death envelops the makeshift morgue as Diego Casallas uses a box cutter to slash open a mud-caked body bag. The unidentified remains are all but decomposed after more than a decade in the ground, but there are valuable clues: a pair of brown work boots and a camouflaged backpack.

"These are objects that can lead to an eventual identification," says Casallas, a forensic anthropologist, as he calmly inspects a femur bone with the cold detachment required of his profession.

As a deal to end Colombia's half-century conflict nears, this lonely cemetery in a former rebel stronghold has become a hive of activity. The past two weeks, criminal investigators have been digging up the dead in hopes of identifying 464 people buried in unmarked paupers' graves. So far, they've disinterred 66.

It's slow work. Every exhumation is documented by forensic anthropologists, topographers and crime scene photographers under the supervision of a prosecutor before samples can be sent to Bogota for DNA analysis, and hopefully, a match with an expanding genetic database of thousands of Colombians whose loved ones disappeared during decades of fighting.

If the detective work succeeds on a large enough scale, it could go a long way in helping Colombians heal from the bloodshed and regain confidence in the rule of law.

In October, as part of a breakthrough in three-year-old peace talks, government negotiators and the Revolutionary Armed Forces of Colombia agreed to establish a high-level agency to search for the bodies of the estimated 45,000 people who were believed to have been slain by one side or the other and whose bodies were discarded without record during the conflict. An additional 220,000 people are confirmed to have been killed.

Authorities for now are concentrating the search in the Sierra de la Macarena, a wild, Taiwan-sized region long disputed by government troops and the FARC.

Human rights groups applaud the effort but say the scope of Colombia's bloodletting requires more resources. Casallas is one of just two dozen forensic anthropologists employed by the chief prosecutor's office, whose job it is to sift through more than 21,000 unmarked tombs and graves nationwide containing so-called NNs, or no names, the term used to describe the anonymous dead.

"If we keep going at the current pace, Colombia is going to be looking for our disappeared for at least the next three generations," said Pablo Cala, an activist who has helped authorities hand over to their families the remains of 108 victims of the 2,292 people buried anonymously in the Macarena region.

The cemetery in La Macarena has long been a symbol for leftist critics of the government. Its location, a few feet downslope from a military base belonging to the elite Omega Task Force, one of the largest recipients of U.S. counterinsurgency aid, fueled tales that it held untold numbers of civilians killed by the military and dressed up as guerrillas to hide human rights abuses. Colombian media took to calling it the world's largest mass grave.

It is unknown how many of the dead were civilians. In a fatal omission that speaks to longstanding institutionalized neglect and corruption in Colombia, authorities at the time made almost no effort to identify the dead or investigate how they were killed.

Such distinctions matter little to Jesus Antonio Hernandez, who for three decades was the village's gravedigger. During the worst of the bloodbath starting in 2002, after earlier peace efforts broke down and the government launched a major offensive, helicopters would unload as many as 10 corpses a day on the base's airstrip, which is the dusty jungle crossroads' only paved surface.

"It was very sad," Hernandez said, wiping away sweat as he wielded a spade helping undoing his burial work. "People were buried without their loved ones. I just put them in a bag and interred them."

While Hernandez took great care to dig individual plots, he said the closest they ever got to a proper burial was a visit years later by a Roman Catholic priest who delivered a prayer for the dead. He left the town himself three years ago, fleeing what he said were death threats by rebels who accused him of helping authorities cover up abuses. But he returned temporarily to assist in the investigation.

With the guerrillas in retreat, the village of 6,000 people is much safer now, but not everyone wants to dig up the past.

Residents whose families have lived for generations in brightly painted shacks adjacent to the cemetery say they want nothing to do with the probe and the conservative mayor is concerned that negative media attention will deflate a nascent tourist boom driven by the town's proximity to the spectacular Cano Cristlaes, a moss-covered river that resembles a floating rainbow when in full bloom.

Ramon Castro, one of the few residents who don't shy away from talking about the past, said many families allowed themselves to be corrupted by the FARC, selling them coca used to make cocaine and even encouraging their children to enlist in exchange for the rebels' money.

But he said that living in a heavily militarized zone, they also came to mistrust the armed forces, to the point that one mother he knows avoided reclaiming her son's body for fear of being labeled a guerrilla sympathizer and putting at risk the lives of her other children.

In an isolated area where justice has long been served at the barrel of a gun, nobody puts much faith in a deal to end the fighting, he added.

"If you ask anyone here about peace they just laugh," Castro said.

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Joshua Goodman is on Twitter at https://twitter.com/apjoshgoodman His work can be found at http://bigstory.ap.org/journalist/joshua-goodman