Caesar's companion, a younger alpaca named Fuzzy Charlie, escaped and was found unharmed.
Alaska Fish and Game officials helped search the zoo for the bear after it killed Caesar. They used forward-looking infrared scopes, but the bear had left the zoo.
"We made sure that all of our animals were where they belong, all our bears were still in their enclosure and our tigers and all the other animals were unharmed," Lampi said.
Fish and Game officials set up cameras to watch for the bear to return. It was killed the second time it came back.
Lampi said everyone was sorry the bear had to be put down.
"It was kind of a bizarre incident," he said.
The zoo is located in near the foothills of the Chugach Mountains.
"There are occasionally bears in the area but they are usually not a problem," Lampi said. "This one just had developed some bad habits."
- Associated Press