The Minnesota dentist who killed a well-known lion in Zimbabwe won't be charged or warned in connection with a complaint that a truck had illegally herded deer inside his property in northwestern Minnesota, the state's Department of Natural Resources said Thursday.

The agency concluded there was not enough evidence after investigating the November complaint of illegal hunting activity against Walter Palmer at his property in Barnesville. The report came from Leah Thompson, who told The Associated Press that she saw pickup trucks chasing deer on Palmer's land while she was hunting nearby.

Chasing or herding deer with a motor vehicle is illegal in Minnesota, punishable by a $200 fine.

But Department spokesman Chris Niskanen said witnesses of the alleged incident weren't able to identify a suspect and investigators couldn't match the trucks described to Palmer or his property manager. Both Palmer and his land manager declined to speak with investigators, Niskanen said.

"In this situation, we just did not have enough info to warrant any kind of charges or warnings," he said. "The DNR exhausted all avenues in this investigation and the case is closed."

A representative for Palmer referred to an earlier statement, calling the complaint false and a baseless attack. The statement said neither Palmer nor his guests were on the Barnesville property at the time of the alleged incident.

The dentist in July was identified as the killer of Cecil, a famous lion in Zimbabwe's Hwange National Park, sparking worldwide condemnation.

Zimbabwean authorities said Cecil was lured out of the park with an animal carcass before he was shot. They later said Palmer had not broken the southern African country's hunting laws, but his guide faces charges of allowing an illegal hunt.