They went to his house Thursday to question him and search for clues in the infamous koala caper. But when police inspectors arrived at the home of a 15-year-old boy believed to have stolen two furry marsupials from the San Francisco Zoo this week, they found a test tube of explosives, a handgun, a spring baton, and steel knuckles with sharp points, according to a police report.
"Holy smokes!" Inspector Lou Bronfeld recalled saying when he saw the boy's paraphernalia.
He and his partner, Inspector John Cleary, called the police department's explosives unit, which took the container of potassium nitrate to a parking lot at 3-Com Park, where it was detonated and destroyed. Potassium nitrate is a white crystalline substance used to make fireworks, explosives, matches, rocket propellants and fertilizers.
A test tube of ammonium nitrate "can take your hand off," said Timothy Culbert, a retired member of Maine's police bomb squad who now operates a Web site on how to deal with bomb threats. "It doesn't take a lot of explosives to hurt or kill you."
According to Bronfeld, the boy said he got the explosives "unexpectedly" and "didn't know what to do with them."
On Tuesday, the 15-year-old and a 17-year-old accomplice were arrested on felony charges of burglary, grand theft and possession of stolen goods after police, acting on an anonymous tip, rescued the stolen koalas from the older boy's Visitacion Valley home.
But the younger boy may be in double trouble, police said. He was already on probation. He now faces felony charges for possession of explosives and dangerous weapons in addition to his problems over the koalas, which police say he and his friend wanted to give to their girlfriends as belated Christmas gifts.
The media frenzy surrounding the koala heist seemed to be subsiding, and the koalas _ Pat, 15, and her 7-year-old daughter Leanne _ began to recover from the trauma. Going without food or water for nearly a day, the animals lost about 12 percent of their 11-pound body weight. Gaining the weight back will be difficult because the animals have virtually no body fat.
The animals, which spend most of their time perched in trees, were kept on the floor and in crates, "essentially walking on a tightrope" during their day in captivity, said their keeper, Nancy Rumsey.
"I'm banking on there being no long-term physical stress," Rumsey said.
Although the animals seem to be in good condition, they have been exhibiting some unusual behavior. Typically they eat with their paws and in private; since their return, they have been eating out of their caregivers' hands, and sticking their noses right into the eucalyptus leaves from which they get food and water.
"They're eating voraciously," Rumsey said.
And Pat, who was treated recently for an eye infection and has a potentially cancerous growth on her face, hasn't been sleeping well, Rumsey said. Normally koalas sleep between 18 and 22 hours a day, but she's been waking up often, appearing irritated.
"They endured something horribly frightening, and koalas don't handle stress well," Rumsey said.