A Delaware man has been charged with stealing the thumb of a $4.5 million terracotta warrior figure on display at the Franklin Institute in Philadelphia.

Michael Rohana was attending a Christmastime ugly sweater party at the museum when he entered the closed-off loan exhibition room, took a selfie with the warrior, and allegedly broke off the thumb as a souvenir from the 2,200-year-old Chinese sculpture.

News of the December theft provoked anger in China. An unidentified Chinese official called for the "American side to severely punish the person who committed this desctruction and theft of mankind's cultural heritage."

The Franklin's loan exhibit, through March 4, features a rare collection of 10 life-size clay warriors discovered at the burial complex of China’s First Emperor Qin Shihuangdi, as well as significant artifacts from the site.

In January, the FBI’s Art Crime Team used security video and credit card information from the party to identify Rohana, and the thumb was recovered from a drawer in his home.