'There is no perfect crime': inside the real French CSI

A new police science unit in France is deploying groundbreaking forensics and believes DNA will soon allow it to put faces on suspects

Imagine a crime scene. The body of a man in a red sweatshirt and jeans lies dead on the living room floor of an apartment, a revolver near his right hand. There is a blood stain on the blue patterned rug and a bullet hole in the ceiling. On a low table sit an almost empty bottle of whisky and two glasses. The television is off.

If this were an episode of the French TV crime drama Engrenages (Spiral) which ran for eight seasons, or the more recent Netflix hit Lupin, the mystery would have been solved and the killer caught before the screen credits rolled.