Only the Truth (1975)

Original title: Kun sandheden

A woman, Ilse Brehmer, finds the body of a dead man, a journalist. He has been murdered, and later when the body turns up in the harbor, the woman denies everything, even though witnesses has seen her nearby the crime scene. She simply can’t remember anything, but the detective on the case, Mørck, knows how to smell a lie and soon start to unravel this bloody mess.