The leftist guerrillas are in peace talks with the government to end a 53-year conflict that has claimed 260,000 lives.
Today, the leftist guerrillas -- the last active rebel group in Colombia -- are in peace talks with the government to end a 53-year conflict that has claimed 260,000 lives.
Otoya, meanwhile, is a 28-year-old artist who has dedicated himself to painting giant pictures of the violence perpetrated by the ELN, or National Liberation Army.
It is, he says, an important reminder of the country's bloody history as it seeks to achieve lasting peace.
It is also a form of therapy for his own terrifying childhood experience of the war.
"I am traumatized, and I decided I was going to talk about it," he told AFP.
"Victims of the conflict have long remained silent... For me, capturing all that in a painting has been a way to get it out."
It was an ordinary Sunday in 1999 when Otoya and his family were kidnapped.
As they sat through mass at La Maria Catholic church in the city of Cali, some 20 soldiers rushed inside and said they had to evacuate the building because of a bomb.
But the "soldiers" were actually ELN rebels in disguise.
They seized 180 hostages -- one of the largest kidnappings in the history of a group that has funded itself with ransom payments.
Otoya was released almost immediately since he was so young.
But his parents and brother were held captive for six months, released only after the family paid a ransom.
Otoya lived with an uncle while they were in captivity.
It was then that he turned to painting.
"What I remember most is my mom's face -- a face I can't shake from my memory, a face of anguish at leaving me all alone," he said.
With a realistic yet dreamlike style, Otoya paints giant canvases measuring two by two meters (yards), reproducing news photographs of the La Maria kidnapping.
Painting the "atrocious act," he says, is a way to heal the wounds of "hate and powerlessness."
Achieving peace, he says, will be "a long, hard job."
But, he adds, "Let's hope it's possible."