If you invite me into your home for a limited purpose (waiting for a friend) and then I attack you, (or as also charged in this case, I steal something of yours)  the legal implied 'invitation' is revoked by your conduct. 

The victim is the 'witness' the jury will hear.  And they will be instructed that ANY fact can also be proven by circumstantial evidence.  

You know, like a hammer, mace container, bruises that match the head of  the hammer, that sort of circumstantial evidence.

And since this guy already has a criminal record, he won't be testifying because that is also admissible evidence, it is going to be the guy who was maced and assaulted's word against.....NOTHING!

Except maybe  the conjecture,  guesswork and speculation reflected in  your comment.  And the jury will be told that "Guesswork, conjecture and speculation can have no place in their deliberations".  

You need to get back your Trump University Law Degree money!  You was robbed!