Walter Palmer, the 55-year-old man who set off an international fervor by killing a lion in Zimbabwe, returned to work at his dental practice on Tuesday morning without saying a word. Palmer closed his Minnesota office for six weeks after it was discovered he paid $50,000 to kill Cecil the lion near Zimbabwe’s Hwange National Park. “This has been especially hard on my wife and my daughter,” Palmer told the Minneapolis Star Tribune. “They’ve been threatened in the social media, and again…I don’t understand that level of humanity to come after people not involved at all.” Palmer denied he had been in hiding, adding that he was out of the public eye to “see family and friends.”