Nick Knight from Forever Knight
Nick Knight and Forever Knight significantly influenced how other vampire shows were made. Nick is the main character of the 1990s series. He was initially a knight from Brabant and became a vampire in 1228. Nick rejects the vampire lifestyle after years of killing to sustain himself. This has also set him on the part of trying to recover his mortality.
Nick also attempts to repay society for the killings he was involved in. And how does he do this? He joins the police force. He goes on to work as a homicide detective for the police in Toronto.