Dozens of protesters gathered outside the practice of a suburban Minneapolis dentist who killed a protected lion in Zimbabwe.
Demonstrators carried signs and chanted outside the office of Walter Palmer, the man who killed Cecil the lion.
Palmer has said he believed the hunt was legal and didn't know about the lion's status as a protected animal.
Some of Palmer's patients were among the protesters.
Signs read "Killer" and "I am Cecil" - the name of the dead lion and protesters chanted "extradite".
Signs also were taped on Palmer's office door, including "ROT IN HELL" and "PALMER There's a deep cavity waiting for you!"
Police were present at the scene and allowed the peaceful protest to continue.
Meanwhile, a professional hunter has been charged in Zimbabwe for failing to prevent the unlawful killing of Cecil, whose death has caused widespread revulsion across the world.
The head of Zimbabwe's safari association said the big cat with the black mane was lured into the kill zone and denied "a chance of a fair chase".
The Zimbabwean men were accused of aiding Dr Palmer, who reportedly paid £32,000 to track and kill a lion.
Zimbabwe police have said they are looking for Dr Palmer, whose exact whereabouts were unknown.
Palmer has reportedly advised his patients to seek care elsewhere as he remains in hiding since his identity was revealed.