Those who collected trinkets and trophies usually kept them, while others kept records of everything they had done, so that they could remember and reminisce about it all.
Some of those things they kept were physical things that belonged to their victims, while some others resorted to taking something else, like a part of their body.
Some collected blood samples while others collected strands of hair, fingers or anything that could be taken and kept stored away and hidden.
The only way for them to avoid something that was a part of their victims from being found by someone was if they were a cannibal and, rather than taking trophies, they were taking a piece of their victims to eat, leaving no evidence of their connection to their crime near them.
Anything that did not belong to them and had the DNA on it could be used as evidence, even if it was a collection of hair accessories taken from each victim or something else.
