Can a person die before their lifespan ends? So we all know, that everyone in Death Note has a lifespan and one day, they'll die when their lifespan runs out. But doesn't that mean, that the victims who get killed by a serial killer are destined to being killed by him? Or are their deaths destined the moment a serial killer decides to kill them?
The people can be killed before their lifespan ends using Death Note. The lifespan of a person is decided by fate and doesn't keep on changing, like when a serial killer decides to kill that person, his lifespan changes. No, the lifespan is already decided, so if the lifespan is already short the serial killer succeeds; if it isn't, the serial killer fails. Also, if a Shinigami writes someone's name which in turn increases the lifespan of others, that Shinigami dies. Humans don't have this problem while using Death Note.