Mörderjagd [Killer Hunt]

Uncover the killer! A body has been discovered and you are the investigative team tasked with finding the killer. Examining the crime scene and the corpse yields some clues. But how is it all related? A letter was also leaked to you, but unfortunately an important part was torn off. The victim, who had a criminal record, was not socially acceptable and his police file reveals 6 suspect names. But who is the culprit?