What degree murder is this?

I just read black cat by Edgar Allan Poe and we’re working in groups in class and part of the assignment is to figure out what degree murder this is. I think it’s either voluntary or involuntary manslaughter. Basically to summarize what happened in the story is he had a black cat named Pluto which he thought was a witch. He killed the cat and the next day his house caught on fire. He thought that Pluto was trying to kill him. After a while he realizes that killing the cat was wrong so he gets another black cat that he thinks is a reincarnation of Pluto. He starts to hate this cat and when it almost trips him on the stairs he goes to kill it with an axe. His wife puts her hand on his arm to stop him and without much thought he swings the axe at her and kills her. Then without any emotion he puts the body in the wall.