Accidental Harrycrux : a question

[zgirnius]

No: HPFGUIDX 155220

 
> Luna:
> I have a question for you guys:
> According to Slughorn, in order to create a Horclux, you need to
> kill someone and perform some kind of incantation in order to have
> your soul split.
> According to DD, Voldemort wanted to create his last Horcrux while
> killing Harry (note that he intended to do it with Harry's death,
> not with James' or Lily's deaths)
> We know that when Voldemort casted the killing curse against Harry,
> it rebounded (thanks to the protection Lily gave to Harry and that
> required her won death in order to be activated), "killing"
> Voldemort himself...
> Now, how can a Horcrux have been accidentally created if Voldemort
> didn't achieve the killing of the victim in the first place, which,
> in theory, is the main requirement for the creation of a Horcrux?

zgirnius:
While Voldemort did not achieve the killing of *Harry* he had just 
achieved two other killings, those of Harry's parents. So pieces of 
soul for encasement were available. Slughorn did not say the spell 
was for splitting the soul-that is an inevitable consequence of 
murder, as he explained. The spell is for encasing a soul bit into an 
object.