It's the intent.Eeh i dont buy it
A murderer that murder prostitutes is a murderer
A "murderer" that murder murderers is a vigilante
especially if those murderers are fully capable of keep on murdering
Im not a lawer, but im pretty sure the diference from a killing to a murderer is some one's innocence
Spica murder those murderer not to enact justice. If she want, she could frame the shit out of them and get them to jail easily. But no, she does murder like fixing a misbuttoning button on a cothes, aka, a satisfaction. She does this so she feels like cleaning a shit from a street.
Like this old man here. He already got dementia, couldn't remember shit. What spica did? Oh he should remember all what he did then i will kill him. She doesn't kill him right away. She is chasing that satisfaction, she is chasing that dominating the once used dominating person.
It's still under vigilantism act though. But just because it's vigilantism, it doesn't mean she ain't psychopath.