What do we know about Axel?
* Axel is a criminal. The reason for his conviction hasn't been stated.
* Axel wants to be part of the community. After the death of the others, he raises the possibility of him and Oscar joining the group with Rick.
* Axel has mechanical skills. In one of the episodes, he is mentioned by Darryl as working on the generators.
I doubt very much that Axel will turn against the community, or take any action that would threaten his standing with the community.
If there is a death, I think it might be Maggie or Glenn, or the person who fell in the prison. (See trailer.)