The U.S. Fish and Wildlife Service says it is investigating Minnesota dentist Walter Palmer, a hunting enthusiast who has been identified as the person who illegally poached Zimbabwe's famous "Cecil the Lion."

But officials are asking the public for help in locating Palmer, who has apparently gone into hiding after his identity was made public and social media lit up with scorn and vitriol.

"I'm sure he knows" that the government is looking for him, Ed Grace, chief of law enforcement for the U.S. Fish and Wildlife Service was quoted as saying in The Washington Post. "We've made repeated attempts to try and get in contact with him."

Meanwhile, partly in response to the incident, the United Nations unanimously adopted its first-ever resolution to combat illicit trafficking in wildlife. According to The Associated Press, the resolution, sponsored by Gabon and Germany, was approved by consensus, but is not legally binding.

The White House also said Thursday that it will review a public petition to extradite Palmer to Zimbabwe over the illegal hunt after the petition surpassed a 100,000 signature threshold. Administration spokesman Josh Earnest said it was up to the Department of Justice to decide on extradition requests from Zimbabwe.

In a statement issued Tuesday, Palmer said he believed "everything about this trip was legal and properly handled and conducted."

The bow-and-arrow hunter said he "had no idea that the lion I took was a known, local favorite, was collared and part of a study until the end of the hunt."

"I have not been contacted by authorities in Zimbabwe or in the U.S. about this situation, but will assist them in any inquiries they may have," he said.

The Star Tribune reports:

"Zimbabwe game officials said Tuesday that two of Palmer's guides are facing charges in the incident and that they 'are looking for Palmer.'"Palmer, 55, who pleaded guilty to a license violation after shooting a black bear in Wisconsin in 2008, said he has not been contacted by any authorities in Zimbabwe or the U.S., but added that he will cooperate with investigators. The public-relations firm that worked with Palmer on the statement said he was in the Twin Cities on Tuesday."Copyright 2016 NPR. To see more, visit