Succubus Lost, Banshee Charmer, and Lycan Unleashed, by Tiffany Allee (From the Files of the Otherworld Enforcement Agency)
From their Amazon descriptions:
“Someone is kidnapping and incinerating otherworlders beyond recognition, and detective Marisol Whitman, a succubus, races to find the murderer before he claims another victim. But her pursuit is derailed when her responsible younger sister vanishes. Marisol suspects foul play and enlists support from an unlikely source: an agent from the Otherworlder Enforcement Agency, Valerio Costa.
When the trail pointing to everyone from vampires to witches dries up, Agent Costa admits to knowing more than he’s shared. Marisol’s sister’s kidnapper harnesses more magic than she can imagine—and they’re running out of time. To find her sister before her powers are drained and twisted beyond recognition, Marisol must connect the dots between cases and put her trust in Costa, a salamander who may burn her before she can solve either case.” [Read more…] about FROM THE FILES OF THE OTHERWORLD ENFORCEMENT AGENCY