I don't think there is any doubt that a thief is a liar. He has to lie many times to conceal that he sneaks around and steals other people's items.
I'm not sure that a liar is always a thief. I think a liar is a thief most times but not all.
I'm not sure that a liar is always a thief. I think a liar is a thief most times but not all.