It seems fitting that in mystery novels, where things and people are seldom what they seem, you would also find a number of authors who write under pseudonyms, aliases, pen names, etc. Just like some of their characters, mystery authors use assumed names to conceal their identities for a variety of reasons.
Writing under an assumed name is not a new trend. Historically, many women would write under men's names to hide their gender in a male-dominated profession. One of the most well-known examples is English novelist Mary Anne Evans, who used the pen name George Eliot. Sometimes women authors would use initials instead of first names (P.D. James), or gender-neutral names.