D.I.D. 12 Episode 16

A detained suspect reveals information that leads police to the remains of a woman killed thirty years ago. At the same time, Fu Shing Shan, the son of Fu Tak Sin, is found dead in an apparent suicide. Meanwhile, Ho Miu Suet learns that Ding Lok Fung has been secretly monitoring her. After her shop is set on fire, Lok Fung's investigation leads to Ding Siu Yan, who unexpectedly admits responsibility and is arrested. Elsewhere, Ying Hoi receives the autopsy report on the unidentified woman, while police discover that Fu Shing Shan's suicide note contains a confession to murder. (Source: Chinese = TVB || Translation = KamilaRN at MyDramaList)