What does the term killer's signature mean when applied to a serial killer?

A 'killer's signature' is something they leave behind, or something they do at every killing they have committed. It can be something like a note, or an item that they live with the bodies of their victims. It can also be an article or something that they take from each victim, that is the same in every case.

It is alot of different things. How the victim was murdered, what they were murdered with, the type of victim, if anything was taken from the victim like a trophy, or if anything was left with the victim like a flower, whether the victim was buried or put on display and where the burial or display took place.

Hmmmmmmm, good question. I think what they mean by a 'signature' is that they always leave a clue behind. Some serial killers do the same kind of thing over and over, and that is his signature. Like, if one used some kind of chloroform on the victim, chances are better than good that is his indentifying method. Or maybe the way they prey on their victims is done in the same manner, or the way they kill them, or dispose of the victims body. Sometimes the profile of how the victim was killed can solve a different killing in a different state, quite often because of the killer's signature of the way he did the crime. Not positive on this all, but that's how I interpret it's meaning.

Hi, twistedangellinda. I would say that he defines it as, symbol, or number that he is using to kill others. He wants to leave abstract clues, like pictures, signs and notes..