Detective Onion was the department's best investigator, dedicated, clever, he knew all the tricks to pacify a criminal with almost anything. So the perfect cop, maybe a little embittered but that's just part of the job, or so he believed. He thought very highly of himself, never mind he had yet to catch a suspect alive and had thus caused a quite big bill to the department and had almost been fired. No matter, it's all a part of the job.
The serial killer, who Onion had been chasing for a month now following clues, which only he could find, had earned the nickname "Scissors" around the department. This was earned for the fact that the unknown killer always left a pair of scissors at the body and one less finger then the victim had before death. Onion thought this was quite dumb, why the hell should someone collect fingers? And why leave the scissors; it makes it obvious that he, whoever he was, was involved. Was he trying to brag with his kills? Why not just leave a name at the victim