Which fallacy is committed in the following statement? 'Tarun cannot be guilty of murder since there is no way Tarun could kill someone.'

The reason simply repeats the conclusion, so it begs the question.

'There is no way Tarun could kill someone' asserts he is not a killer.

'Tarun cannot be guilty of murder' says essentially the same thing.

The premise thus presupposes the very point in dispute.

An argument that assumes its own conclusion begs the question.