Hang about in covert ops style after kicking the door in and see who turns up, if its not the bloke run over and grab whoever he is, shove him in the back of the covert van and scare the shit out of him whilst asking who the feck the bloke who robbed you was.
He'll fess up if he knows the bloke.
Stick paintstripper across his cheeks after tieing him up
br a cunt if the guy was just there to read the meter