ARGENTINA — Bonnie and Daniel Loedel walked into a mausoleum with an urn holding the bone remains of their sister Isabel, who had been unidentified for four decades after being forcibly disappeared during Argentina’s military dictatorship.

Delivering the simple wooden box was the last step of an arduous identification process that they hope will bring the family closure and, at the same time, thwart the goal of the military regime that human rights groups estimate killed or disappeared 30,000 people while seeking to make its victims invisible.

The Remembrance, Truth and Justice Mausoleum for the Victims of State Sponsored Terrorism is at a cemetery in La Plata, a town about 35 miles from Argentina’s capital of Buenos Aires. It holds the remains of at least a dozen people who were disappeared during the dictatorship.

The remains are a few of those identified by the Argentine Forensic Anthropology Team, an independent group of scientists who developed their expertise identifying victims of the 1976-1983 military junta and have since helped unravel human rights atrocities in more than 50 countries.

Friends and family of Isabel Loedel recently gathered at the mausoleum to say goodbye to Isabel, whose remains were identified only last year. She has now rejoined her partner, Julio Di Giacinti, who was identified by the forensic team seven years ago. Both were killed in early 1978 by dictatorship agents.

The Argentine Forensic Anthropology Team has been working since 1984, a year after Argentina’s return to democracy. It has recovered the bodies of more than 1,400 disappeared people and identified 795 of them.

The genetic profiles of the approximately 600 remains that are unidentified don’t match any of the samples in the team’s database. So the non-governmental group has launched a campaign urging more relatives of the disappeared to provide blood samples to help identify the remaining bodies and allow them proper burials.

The process not only gives a name to the invisible. It also reconstructs their stories and suffering, allowing their loved ones to complete their grieving.

“What they do is extremely important. It brings closure,” Bonnie Loedel said of the team.

“You can let go. You can celebrate their lives and you can let them go, and at the same time it reminds us we can’t ever forget…you cannot erase people, make them invisible,” she said of her half-sister, who was 11 years older.

Still, Bonnie said, she has only vague memories of her much older sister. “Isabel was this mysterious person,” she said.

Blood samples given by Daniel Loedel and his father, Eduardo Loedel, let the forensic team identify Isabel’s remains, which had been recovered in 2010 from an unmarked grave in a cemetery in Buenos Aires province. The analysis also determined she died after sustaining multiple injuries, most of them in the chest.

“It’s been 40 years,” Bonnie Loedel said. “When somebody disappears, you can’t grieve, she has disappeared. Taking the blood test and finding her was amazing.”

Giving blood samples to identify a loved one who died in violent circumstances is a delicate psychological process that can bring back haunting memories.

“It takes a long time to muster courage to do something so simple,” said Daniel Di Giacinti, who provided a sample to identify his brother, Isabel’s partner. “It sounds easy, but it’s not. It was extremely hard for me, and I was a (political) activist.”

Juan Carlos Barrera, a member of the Montoneros guerrilla group, was identified under a forensic team initiative in 2009 thanks to a blood sample given by his daughter, Angela. But coming to grips with the past was painful, she said.

“Just calling (the team) was tough. I called several times and hung up,” Barrera told The Associated Press. When she finally stayed on the line, she found the team also would provide her with emotional support and she agreed to go ahead.

Her father was kidnapped by dictatorship agents on April 7, 1976, when Angela was 3 years old. For long, she felt she had “reached a dead end,” and found it extremely difficult to talk about being the daughter of someone who had been disappeared. Though the forensic results determined her father died after suffering from burns and multiple broken bones, she said the identification process was healing.

Luis Fondebrider, executive director and founding member of the team, highlighted the importance of the new campaign.

“It will probably be the last far-reaching attempt” at identifying the recovered remains, he said.

The team works in the former Naval Mechanics School, which was a notorious clandestine detention and torture center that held an estimated 5,000 prisoners and is now a museum for remembrance.

Fondebrider said identifying bodies “gets more difficult as the years go by because not all relatives are sufficiently close” genetically.

“Parents are ideal, then come the siblings, the children,” he said. “The statistical percentage is reduced as the distance grows.”