DNA is different because it identifies you directly. That creates a chilling effect. The likelihood of someone not reporting a burglary to the police because in

DNA is different because it identifies you directly. That creates a chilling effect. The likelihood of someone not reporting a burglary to the police because in a few years they might want to murder someone with their unique sword is… low. Rape is already infrequently reported because police are often hostile; we definitely don’t want to add that a crucial part of the victims will be forever on the police’s radar, just in case it ever becomes relevant, to be used as evidence against them.