SOGAMOSO, Colombia (Reuters) - Margarita Lucia Fonnegra did not flinch when the needle pricked her finger. Others had needed reassurance from the forensic technician but the 71-year-old Colombian grandmother was ready.

What was a little blood if, after 13 years, she finally got answers?

Margarita’s son, Carlos German Daza, was a 33-year-old mechanic when he disappeared on Aug. 12, 2004, from the town of Puerto Boyaca in central Colombia.

Carlos German left home after receiving a phone call and never returned, one of at least 52,000 Colombians who went missing and were likely killed during five decades of civil war.

“Sometimes I think it’s a dream: that there’s been a mistake and he’ll turn up,” Fonnegra said after her bleeding finger was pressed to a sample paper, its bright drops containing all the laboratory needed to check her DNA against a register of unidentified bodies.

Fonnegra and her grandson Juan Guillermo Daza, 24, came to the industrial city of Sogamoso, high in the Andes, to find the missing generation between them.

The rumor in Puerto Boyaca, a port town on the banks of the Magdalena River that was hard-hit by the civil war, was that Carlos German reported a cocaine lab to authorities and was killed by a right-wing paramilitary death squad, his son said.

Paramilitary groups were formed by landowners to guard against attacks by the leftist Revolutionary Armed Forces of Colombia (FARC), but soon became brutal drug-traffickers. Daza was not yet 10 when his father disappeared.

“I still had so much to discover about him,” he said, recalling his dad’s love of stargazing and big Christmas celebrations. “We want to mourn.”

The family reported his disappearance, unlike many who stay silent for fear of reprisals, but the case never progressed despite testimony from a demobilized paramilitary about the body’s location.

Now they hope a DNA database donated by the U.S. Federal Bureau of Investigation, which compares samples from families with those from unidentified bodies, will help to locate his remains.

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“If they find him and give me some bones, I’d be very happy,” Fonnegra said, weary after a 15-hour bus journey. “But there’ll also be sadness because it hurts so much when your children are harmed.”

NEW TECHNOLOGY

Colombia has been using DNA to identify bodies for 15 years. The latest version of the CODIS software being supplied by the FBI, mentioned in myriad television dramas, has been in use in Colombia since 2015.

It is designed for unidentified remains and lets extended family members contribute samples, increasing the chances of a match.

Parents and children offer the most identical genetic markers, but the ability to identify bodies using samples from more distant relatives is significant in Colombia, where the conflict’s long duration means many parents of the missing are beginning to die themselves.

The system has so far turned up just 156 matches, but there are now 3,658 unidentified bodies registered and more than 35,000 samples from families.

The new software comes as Colombia emerges from a war that killed more than 220,000 people, not including the disappeared. A peace deal between the government and the FARC was signed in 2016, ending 52 years of fighting.

Providing answers about the disappeared is a key part of the agreement. Implementation, however, has struggled amid separate talks with a smaller guerrilla group, the National Liberation Army (ELN), which is still launching attacks.

The FARC handed over thousands of weapons to the United Nations last year and reorganized as a political party. Though most fighters will receive amnesty, commanders will face trials for alleged war crimes.

Victims hope trials will reveal information about the missing, but a paramilitary demobilization a decade ago yielded little useful testimony. Fighters were required to share grave locations as part of a deal for reduced jail time, but many finished their prison terms and were released without doing so.

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Colombia is unlikely to put the conflict to rest until people can bury loved ones. Yet experts warn that it faces a greater challenge than Argentina, Chile and Guatemala, where the disappeared were victims of the government, because the presence of multiple armed groups complicates searches.

Colombia’s military also disappeared people, including for profit after the government began paying bonuses based on a unit’s number of supposed rebel kills.

The head of a new investigative unit that was created under the terms of the FARC deal recently warned that the disappeared were not getting enough attention. Victims’ groups also decry government inaction and say the number of missing may be more than 90,000.

‘NO MATCHES’

Clandestine graves are often in rough terrain, their exact locations recalled only by former fighters with hazy memories. Some bodies turn up far from where the victim disappeared. Some families have no idea who took their loved one, nor why.

When bodies are found, samples are taken from femurs and teeth, two types of bone that best protect DNA during decomposition. The fragments are ground into powder and mixed with chemicals to make the DNA readable.

Forensic technician Victor Hidalgo spent a long day in the crowded Sogamoso school auditorium, taking samples for 29 cases over 11 hours. He explained the process to each family, some of whom signed with an X because they are illiterate.

Finally, four months after the families staked their hopes on a match, a database manager in Bogota, Fanny Merchan, ran the results against the register of unidentified bodies.

She hit the enter button.

“No matches,” she sighed.

But she remains hopeful: that morning, she said, they found a match for a father searching for two missing sons.

“It coincides on all markers,” Merchan said, pointing to genetic traits listed on her screen, “the probability is very high these remains belonged to a son.”

It will likely never be clear which son. The remains have been in the system for five years, waiting for someone to come looking.

Daza was saddened to learn there was no match for his father. But he was not giving up, he said by telephone.

“Hope’s always there,” he said. “But the remains won’t last. They’ll disintegrate completely, into dust.”