“The question is, what kind of crime did she commit?“
Jury Says-
Murder!
Yes it did. A jury also let Casey Anthony off.
But nobody even alleged, as far as I know, that she intentionally entered someone else's apartment and killed them. She entered by error.
The crime involves whether she should have shot him even if she legitimately believed he was an intruder in her own apartment. Based on what I know her shooting didn't seem justified, but it's hard to see how it is murder instead of manslaughter.