On Publishing … and Other Forms of Insanity:
Whodunnits never go out of style, and neither do pulse-pounding thrillers, so if you write mysteries or thrillers, you are in luck.
Here are a dozen mystery and thriller publishers that don’t require an agent.
All are traditional publishers. (No vanity presses)
Make sure your manuscript is complete before you submit.
None of these publishers accept proposals or partially completed work.