Reaper's Rebellion. The Falcone Files, #1

Detective Daniel Falcone lives in a world where mythical creatures aren't legends - they're neighbors, coworkers, lovers, and criminals. Vampires walk city streets. Centaurs wear police badges. Merfolk fight environmental collapse. And magic exists beside modern life. For Falcone, a witch detective working Special Investigations, most cases are manageable. until two teenagers die in what appears to be a brutal murder-suicide.
But the evidence doesn't add up. The deeper Falcone and his vampire partner Diana Savina investigate, the more they uncover signs of something impossible: a force capable of overriding free will itself. As time passes and the body count rises, Falcone must find the source of this unknown magic before it forces the city he loves and protects under someone else's control.