In many jurisdictions, the **self-defense** defense for homicide rests on the state of the mind of the suspect, insofar as it can be determined, and failing that on a "reasonable man" standard.

- Presumably **Bob** genuinely felt threatened by **Charlie** and says so afterwards. "I thought he/it/whatever was trying to harm me. I didn't know it was a harmless actor." Just how much harm Bob needs to make self-defense stick varies from jurisdiction to jurisdiction. It could be fear of imminent, serious bodily harm, or fear of being victimized in any sort of crime (*stand your ground* laws).
- The well-documented and extensive efforts by Alice and Darren to fool **Bob** should support Bob's statement. Say the court/jury believes that it was reasonable (or at least "not entirely unreasonable") for Bob to be afraid.
- Since the perceived self-defense would apply *even if* Bob thought the attacker was human, thinking that it was non-human should make little difference. Except that it would further showcase the degree to which Bob was fooled to see a threat. 
- If the whole endeavor by **Alice** and **Darren** broke laws, the death *might* fall into felony homicide in some jurisdictions. This one could come to technicalities because Bob wasn't their accomplice. Otherwise, Darren's track record might prevent the two from being charged for negligent homicide.

Consider the well-publicized cases where either the police or civilians shot unarmed men, and say that they *thought* the victim was armed and a threat to them. If doesn't matter if the victim drew a gun or a wallet, it matters if the shooter can make his or her fears plausible enough.