The two crossword solutions for the term 'First Name in Mystery Writing' are Erle (4 letters) and Diell (5 letters). Erle is the first name of the famous mystery writer Erle Stanley Gardner, who wrote over 80 novels and short stories featuring the popular detective character Perry Mason. Diell is the first name of the British mystery writer Agatha Christie, who is widely considered to be one of the greatest mystery writers of all time.