SAO PAULO, Brazil — Tony was the first to die. They found his body early in the morning of Jan. 24, limp and lifeless, his face a mask of pain.
Three days later, another suspicious death surfaced, with similar signs. By week's end, there were five more.
Soon victims were dying in groups, poisoned by the same odorless, colorless, highly toxic substance. Desperate authorities have tallied at least 62 deaths but acknowledge that they are not close to making an arrest.
Who is killing the animals at the Sao Paulo Zoo?
Since Tony the chimpanzee died, an elephant, five camels, several tapirs, a pair of rare capuchins, an orangutan, some tiny golden lion tamarins and dozens of porcupines have been poisoned in a case that has baffled Brazilian police and horrified zoo officials and visitors.
Law enforcement agencies have mobilized 50 officers -- including nearly a fifth of the city's special operations unit -- to hunt down the serial killer, while zookeepers scramble to beef up security, change feeding routines, install cameras and find ways to cope with a rampage nobody can make sense of.
"It's an unthinkable situation," said Jose Luiz Catao Dias, technical and scientific director at the zoo in South America's biggest city. "We have emergency protocols for escapes, for fires, for flooding, for walkouts and strikes. But the Sao Paulo Zoo had no protocol for insanity."
Worse yet for Catao and his staff, signs point to an inside job, or at least assistance from within -- meaning that a killer may be in their midst, somebody with knowledge of the park's operations and access to its food supply.
Investigators are probing the possibility of a vendetta by a disgruntled worker or former worker, but some employees say they cannot think of anyone who left the zoo under a cloud or who would kill so many defenseless creatures to make a point.
"If it's for revenge, then take it out on a person, not on the animals," zoo biologist Juliane dos Santos Soares said. "Cowards!"
She and her colleagues have been dealing with the horror of seeing so many of their charges die painful, premature deaths. Many of the animals' handlers had worked with them for decades, like Baira the elephant's keeper, who knew her so well after 30 years together that he could tell she was blinking differently one day. He immediately informed his bosses, but the elephant died less than 24 hours later, leaving her keeper in tears. The man is still too devastated to talk about what happened.
