If someone killed another 'person' that turned out to be a space alien, is that murder?

You know the type, one of these secret space aliens on the way to one of their abduction and probing sessions. Anyway, would the alien be classed as a person and would the attacker be charged with murder? Let’s assume the attacker was actually just out to really murder someone for some perverse reason, not defending themselves or anything like that. When the victim is examined, it is quite clear that they are not human and their DNA is nothing like any other living thing.