An American dentist who admitted that he killed a well-known lion this month in Zimbabwe and planned to mount the head kept his office closed on Wednesday as the furor about the hunt turned vitriolic and, at times, threatening.
Dr. Walter J. Palmer’s neatly groomed property near Minneapolis, adjacent to a preschool, has turned from a dentist’s office to a memorial to the lion, called Cecil, with red roses and more than a dozen stuffed animals laid outside the locked front door.
There was no answer to repeated knocks and doorbell rings at his large, stucco house in an affluent neighborhood. And his neighbors would not talk.
In an email distributed Tuesday night to his patients, Dr. Palmer said “media interest” had disrupted his practice and had caused people to overwhelm his staff with comments and phone calls. Patients seeking help were being referred to other offices for the time being.
In the hours after Dr. Palmer apologized for the shooting, saying he had killed the lion under the impression that the hunt was legal, he has gone from a dentist and longtime hunting enthusiast to the villain at the center of a virtual firestorm over the ethics of big-game trophy hunting.
In the message to patients, Dr. Palmer, who prides himself on his skills in hunting without firearms, acknowledged the controversy over big-game hunting.
“I don’t often talk about hunting with my patients because it can be a divisive and emotionally charged topic,” he wrote. “I understand and respect that not everyone shares the same views on hunting.”
Trophy hunting, undertaken by wealthy hunters who pay tens of thousands of dollars for licenses to kill protected animals for trophies and sport, has long been a subject of global debate. Hunting advocates and some conservationists argue that, if done responsibly, the selling of expensive licenses to big-game hunters can help pay for efforts to protect endangered species.
A 2009 study by the International Union for the Conservation of Nature estimated that trophy hunters kill around 600 lions a year. Last October, the United States Fish and Wildlife Service proposed to list the African lion as threatened under the Endangered Species Act, and a move that would also establish guidelines for permitting the importing of lion trophies. That proposal is under review.
When a Texas man reportedly paid $350,000 to hunt and kill a black rhinoceros in Namibia this year, the debate remained among activists. But the death of Cecil, a 13-year-old lion who wandered out of his sanctuary in a national park in Zimbabwe, struck a chord with social media users. Dr. Palmer had paid around $54,000 to hunt the animal, according to news reports.
Cecil had been closely studied by researchers at the University of Oxford since 2008 as part of efforts to study a decline in Africa’s lion population and to better understand the threats the animals face. The university’s Wildlife Conservation Research Unit said in a statement that Cecil’s adult “brothers” and cubs would now most likely be killed by other male lions seeking dominance in the community.
According to the Zimbabwe Conservation Task Force, the lion was shot with a crossbow after he was lured out of the sanctuary, following the scent of food. Cecil, well known to those who visited the Hwange National Park in western Zimbabwe for his jet black mane, was only injured by the arrow. The hunters tracked him for about two days before he was killed with a gun, conservation officials said. He was beheaded and skinned, his corpse left to rot.
On Wednesday morning, Lori Peterson was one of the protesters who assembled outside the dentist’s office. She held a large homemade sign that said “KILLER” in black paint. On the back of the sign, the dentist’s name was painted: “WALTER JAMES PALMER.” She posed for pictures for gawkers and reporters.
“I want to call this man out,” said Ms. Peterson, 52, an artist from Bloomington, Minn. “These animals need a voice.”
As more details around the killing emerged, activists used search engines to find Dr. Palmer’s contact information and social media to share information about his business and his family, stirring a fever pitch of anger strong enough to effectively dismantle his digital life.
Angry people sent a surge of traffic to Dr. Palmer’s website, which was taken offline. Vitriolic reviews flooded his Yelp page — “Murderer,” one reviewer wrote. A Facebook page titled “Shame Lion Killer Dr. Palmer and River Bluff Dental” drew thousands of users. Professional profiles of Dr. Palmer were also scrubbed from industry websites.
Jon Austin, who operates a Minneapolis-based communications firm and specializes in crisis management, said in an email that he had been asked to circulate Dr. Palmer’s initial statement to the news media.
“I 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,” Dr. Palmer said in that statement. “I relied on the expertise of my local professional guides to ensure a legal hunt.”
After the statement was circulated, Mr. Austin’s own Yelp page was flooded by angry commenters. On Wednesday, Mr. Austin said that he had ended his involvement with the matter.
The outrage went mainstream after Zimbabwean officials publicly identified Dr. Palmer, but it expanded into all corners of the Internet after an emotional plea against hunting from the late-night television host Jimmy Kimmel, said Erin Flior, who specializes in crisis management at the Washington-based public relations firm Levick.
In an phone interview on Wednesday, Ms. Flior said that social media outrage has made digital crisis management a growing specialty in the communications field. She recalled extreme cases where clients had to move or look into changing their names.
“While I applaud the attempts of people to draw attention for positive situations,” Ms. Flior said, “it’s always a really scary situation for an individual because you never know how far it’s going to be taken.”
In 2009, Dr. Palmer paid $45,000 at an auction to help preserve an elk habitat in California. He was profiled that year in The New York Times when he shot and killed an elk from 75 yards with a compound bow in pursuit of a new bowhunting record.
Two Zimbabwean men, a farm owner and a professional hunter, are accused of helping Dr. Palmer hunt Cecil. They appeared in court on Wednesday on poaching charges. Zimbabwean officials said Dr. Palmer was also being sought on poaching charges.
In a joint statement, the Zimbabwe Parks and Wildlife Management Authority and the Safari Operators Association of Zimbabwe said that the farm owner did not have a hunting permit. The professional hunter’s license has been suspended, the statement said.
Dr. Palmer has had past problems related to hunting. He faced probation after he pleaded guilty in 2008 to making a false statement to federal officials about where, exactly, a black bear was killed in Wisconsin.
Christina Capecchi contributed reporting.