Here There Be Monsters by Josh Wright

SPFBO10

800 years ago, Witches from another dimension tried to take over the world. 300 years ago, the paranormal beings they left in their wake came out of the shadows to join human society. Now, a knight cursed with immortality, a mummy with eldritch powers, and a werewolf police captain are on the trail of a serial killer hunting paranormals. The reasons why will lead them deep into a world of corruption where religion mingles with politics, humanity's xenophobia is on full display, and the monsters aren't necessarily the ones with claws and fangs.