'Mr. Kubra is a murderer because he wrongfully killed someone.' Which fallacy is committed in the above argument?

Calling Mr. Kubra a murderer because he wrongfully killed someone merely restates the conclusion as its own reason.

A murderer just is a person who wrongfully kills another, so premise and conclusion say the same thing.

The reason offered already assumes the very point it is meant to establish.

An argument that assumes its conclusion in its premise reasons in a circle.

This circular self-assumption is the fallacy of begging the question.