Palmer had a permit to hunt bears within a certain area near Phillips, in the north of the state. But on September 1, 2006, he was part of a group of people who killed a black bear 40 miles outside this permitted zone, according to the court documents from April 2008.
Realizing what they had done, the group agreed that "if any authorities were to ask where the bear had been killed, they would say" it was hunted within the correct area, the documents added.
They transported the carcass to a registration station where they certified the animal had been killed legally, the documents said, adding that the body was later taken to Minnesota, where Palmer lives.
Palmer was charged with knowingly making false statement to an agent of the Department of the Interior, U.S. Fish and Wildlife Service, having "falsely stated that he thought the bear had been killed legally" during interviews with officials the next month.
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According The Associated Press, citing the Minnesota Board of Dentistry, the dentist was also the subject of a sexual harassment complaint settled in 2006. He admitting no wrongdoing and agreed to pay a former receptionist more than $127,000, the AP said.
He was also convicted in Minnesota court in 2003 for fishing without a licence.
Theo Bronchorst and Honest Trymore Ndlovu, the professional hunter and landowner who allegedly "connived" to kill Cecil the lion, were due in court on Wednesday, Zimbabwe wildlife officials said.
Together they are charged with illegally killing the animal because they had "no permit or quota to justify the offtake of the lion and therefore are liable for the illegal hunt," the Zimbabwe Parks and Wildlife Management Authority said in a statement Monday.
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Palmer said in a statement to NBC News: "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."