BLP violation within edits to Roman Polanski? 

The WP:BLP states "If an allegation or incident is notable, relevant, and well-documented by reliable published sources, it belongs in the article — even if it's negative and the subject dislikes all mention of it."

There is no mention as to what specific titles should be or should not be applied. The title of rapist in no way violates this policy, is well documented, and appiles to him under these guidelines.