The two crossword solutions for the term 'First Name in Mystery Fiction' are AGATHA (6 letters) and Erle (4 letters). AGATHA is the first name of AGATHA Christie, the renowned British author who wrote 66 detective novels and 14 short story collections. Her works have been adapted into plays, films, and television series. Erle is the first name of Erle Stanley Gardner, an American lawyer and author who wrote over 80 detective novels and stories featuring the characters Perry Mason and Della Street. His works have also been adapted into films and television series.