The expert lived up to his name. Gao Facai was jumped right into work, and the forensic department kept updating them with the latest news. Gao Facai's first task was to extract a kind of microorganism on the surface of the metal box that was commonly found in soil. He then was able to estimate the year that the metal box was buried underground by analyzing the growth of the microorganism!
According to his estimation, Tao Xiang's metal box was buried in somewhere between ten to thirteen years ago, while Du Manting had died about twenty-one years ago. In other words, Tao Xiang didn't bury the box there right after Du Manting had been buried.