The Washington Post has a very interesting interview with actor David Thewlis (Lupin) from the Harry Potter movies. The article has some interesting questions that we haven't seen before.
WP: Why did they offer you this role?
Thewlis: I don't really know. I had been considered for the role of Professor Quirrell [which Ian Hart played in the first movie, Harry Potter and the Sorcerer's Stone], so I suppose somebody obviously likes me. I felt an enormous responsibility because internationally there's a real passion among kiddies for these books. When I went online to do research about werewolves and stuff, I found all this e-mail chat saying things like, "Who is this person playing Professor Lupin? We want someone good-looking, like Jude Law!"