Warne said he had met Thompson a few times. He used to come into the doughnut shop at one time.

Thompson had his run-ins with the law. He pleaded guilty this year to federal charges of possessing illegal firearms, including five fully automatic firearms, and was released from prison September 30. A civil case seeking forfeiture of firearms is pending, according to the U.S. attorney's office in Ohio's Southern District.

Thompson also was convicted of animal cruelty and animals at large in 2005 and was arrested several times for traffic violations.

Lutz said law enforcement officials were well aware of Thompson's animals and made numerous visits to the property to look into complaints and ensure that Thompson was in compliance with permits

Thompson's property is about 2 miles outside Zanesville, Zwelling said. Authorities said they received reports of animal sightings by residents. Columbus Zoo director emeritus Jack Hanna drove into Zanesville overnight to assist in the search.

But Hanna warned that the search was dangerous and said human life came first.

"We're trying our best to make sure no one is hurt doing this," he said.

He said the animals were probably hiding out from the rain, but his advice to anyone who encountered one was this: Don't run. Just scream.

The menagerie of Thompson's animals also included wolves, giraffes and camels. Commuters reported seeing bears and wolves along Interstate 70. Lutz said one cat was hit and left wounded on the road.

The Humane Society of the United States urged Ohio officials Wednesday to issue an emergency rule to crack down on exotic animal ownership.

A previous emergency order issued by then-Gov. Ted Strickland that prohibited people convicted of animal cruelty from owning exotic animals expired in April.

The Humane Society said Thompson "would almost certainly have had his animals removed by May 1, 2011, if the emergency order had not expired."

"Every month brings a new, bizarre, almost surreal incident involving privately held, dangerous wild animals," said Wayne Pacelle, president and CEO of the Humane Society. "In recent years, Ohioans have died and suffered injuries because the state hasn't stopped private citizens from keeping dangerous wild animals as pets or as roadside attractions. Owners of large, exotic animals are a menace to society, and it's time for the delaying on the rule-making to end."

Fritz Douthitt, a volunteer at the Zanesville Animal Shelter Society, recalled Thompson's 2005 trial for cruelty and torture of cattle and bison. She said he had not been able to get up the hill to feed his livestock, and they died.

Douthitt said it is inappropriate for people like Thompson to keep dangerous animals as pets, just as it was to shoot so many of them. Local governments, she said, ought to train law enforcement officers so they are prepared for bizarre cases such as the one that unfolded in Zanesville.

For lions, tigers and bears to die, she said, was "unforgivable."

CNN's Jordana Ossad, Andy Rose, Ninette Sosa, Ed Payne and Maggie Schneider contributed to this report.