Puzzler

I wake up every Sunday morning anxiously awaiting the release of the
Sunday Puzzler. In an attempt to spread the joy, I will begin sharing these with you here.

Challenge from October 29: Name a well-known writer of the 20th century, now deceased... an author of bestselling non-fiction. There are six letters in the first name and six in the last. Remove the letter "C" somewhere from this name. The remaining letters can be rearranged to name a famous fictional detective with four letters in the first name and seven in the last. What names are these?

I will post the answer when I figure it out, or next Sunday when it is revealed - whichever comes first.