The American dentist who sparked international outrage after killing Cecil the lion in Zimbabwe has reached out to U.S. authorities, U.S. Fish and Wildlife officials said Friday.
A representative for Dr. Walter James Palmer, who has admitted to killing the 13-year-old lion, "voluntarily" reached out to the U.S. Fish and Wildlife Service Office of Law Enforcement on Thursday, the service said in a statement.
Earlier Thursday, U.S. Fish and Wildlife Director Dan Ashe said efforts to contact Palmer had been unsuccessful and urged him on Twitter to get in touch.
Palmer has not been charged with a crime and has said he trusted his local guides to obtain necessary wildlife hunting permits. The guides face fines and jail time for alleged poaching and not having the proper permits.
Cecil was a popular draw for tourists and was tagged as part of a study at the U.K.'s Oxford University. Cecil's death has drawn international outrage.
In Zimbabwe, the illegal killing of a lion is punishable by a fine of $20,000 and up to a decade behind bars, and Zimbabwe's environment, water and climate minister said Friday that officials would appeal for the extradition of Palmer, who has since returned to the U.S.
Related: Cecil the Lion's Killer Should Be Extradited: Zimbabwe Minister
Back home, Palmer has been met with a wave of condemnation. Nearly 200,000 people have signed a petition on the WhiteHouse.gov website to have the dentist extradited.
Another petition seeks to retain the right to flood a Yelp page for Palmer's dental practice with negative reviews — many of which have focused on outrage over Cecil's killing. The Change.org petition was started after Yelp removed many of the reviews. The petition had only been signed by 159 people as of Friday evening.
"Yelp's autocratic censorship of this this historic, unprecedented outpouring of participation in public debate silenced and disempowered their loyal contributors," the petition reads.
A Yelp spokesperson said in a statement released to NBC News that "media-fueled reviews typically violate our Content Guidelines. For example, reviews aren't the place for rants about a business's employment practices, political ideologies, extraordinary circumstances, or other matters that don't address the core of the consumer experience."
"Our user support team ultimately removes reviews that violate these guidelines," the statement said.
Palmer shuttered the doors of his practice and disappeared from public view after word got out that he was responsible for the July 1 kill.