On the afternoon of July 10, 1995, as Bosnian Serb forces closed in on his hometown of Srebrenica, Nihad Catic turned on his microphone and recorded what would be his last, forlorn call for help.
"Srebrenica is turning into a vast slaughterhouse," he shouted, his voice urgent and desperate. "The dead and wounded are continuously being brought to the hospital. Will anyone in the world come and witness the tragedy that is befalling Srebrenica and its people?"
Two decades later, his mother, Hajra, keeps the crackly recording on her mobile phone.
Along with a couple of faded black-and-white photographs, this is all she has left of her son, a radio journalist and one of the more than 8,000 Muslim men and boys slaughtered around Srebrenica during the Bosnian War.
The massacre is considered the worst atrocity in Europe since World War II -- grim proof that threat of genocidal violence still haunted Europe a half-century after the Holocaust.
Nihad, who was 26 when Srebrenica fell, ran the local radio station Voice of Srebrenica throughout the 1992-95 conflict.
When Serb forces surrounded the city, his reports from besieged Srebrenica were widely broadcast across the war-torn nation.
One day after his last broadcast, Nihad, his mother, and his father, Junuz, abandoned Srebrenica and joined thousands of fellow Bosnian Muslims seeking refuge at an old car battery factory that was being used as a base by Dutch UN peacekeepers in the village of Potocari.
But the peacekeepers quickly handed over the base to the Army of Republika Srpska, led by Bosnian Serb commander Ratko Mladic, and Hajra was separated from her husband and her son.
She never saw them again.
Junuz's body was found 10 years later in the town of Kozluk, in a mass grave hidden under a rubbish heap.
Nihad -- Nino to his bereaved mother -- is among the 1,200 Srebrenica victims still reported as missing. Another 7,000 people are unaccounted for after the war, in which a total of 100,000 people lost their lives.
"I'm afraid I'll never find him," Hajra told RFE/RL. "If I could find even just his little finger, I would have a place to honor his memory."
Nihad and Junuz fled the UN compound on foot along with up to 20,000 men and boys in the hopes of reaching territory controlled by the Bosnian Army, some 50 kilometers away.
Most of the Srebrenica victims were caught during the march and executed in nearby fields and warehouses.
Hajra still doesn't know how, or even where, her son died.
Survivors say he was wounded by shrapnel in the woods. His final moments, however, are forever lost in the chaos and death that marked the long trek through the mountains.
Hajra's hopes of finding her son's remains are fading, too.
As a co-leader of the Women of Srebrenica association, she has fought hard to keep the victims' memory alive and ensure that grieving families get a chance to bury their dead.
Her 20-year search for her own son, however, has been fruitless.
"I went to the minefield where he was wounded, but I didn't find anything," she says. "A little further I found a skull, but I don't think it was his; it was too far from that spot. Perhaps my Nino still lies further away, among the remains that have not yet been identified."
Special Project: The Faces Of Thousands Who Died In Srebrenica
The endless task of accounting for the victims continues, conducted by the Bosnian Institute for Missing Persons and the International Commission on Missing Persons.
The odds of finding every single missing person are slim.
The Bosnian Serb Army excavated mass graves in an attempt to conceal evidence of the massacre, reburying the bodies in secondary graves, tipping them off trucks down ravines, or crushing them with bulldozers.
In some cases, bones from one body are found in different mass graves dozens of kilometers apart.
Every year on July 11, remains identified over the previous year are buried in the cemetery at Potocari.
This year, 136 Srebrenica residents will be buried in a ceremony attended by thousands of relatives and dignitaries from around the world.
Once again, Nihad won't be among them.
Despite her growing frustration, Hajra will have no peace until she lays her son to rest.
"I'm losing hope, but I must fight on," she said, choking back tears. "I will search for him as long as I live."