La fille au bracelet

Near to the start, the victim's mother describes huge amounts of blood. With only the face being spared a savage attack. But during the trial, the scene-of-crime photos show no sign of any blood at all; just a few neat wounds. This dichotomy is so extreme that this viewer was entirely distracted from watching the remainder of the movie with any interest. What did it mean? Was it some sort of 'high art' concept? Was it the start of some sort of science fictional adventure? Do the French police wash bodies, launder bed-clothes and wash walls before taking a literally sanitized picture? What does it mean?