Infernal Affairs by Destiny Draco

Isla Andal is trying her hardest to ignore her witch abilities and blend in with the humans. She joined PEACE to help humans and metahumans live in harmony. But when several shifters are discovered brutally murdered in her turf, all her hard work looks to be for nothing. There’s only one person that can help her – and she HATES him.
Even though Caspian Steele has seen it all over hundreds of years, this vampire is not ready to be working with Isla. He can’t stand Isla. Her curvy, graceful body makes him lose focus whenever she’s in the same room and she gets under his cool and aloof façade. She boils his blood and all he wants to do is bite her all over…all night long.
These two are on the same side and masters in their field. But when it comes to love, they’re dumb as rocks. They can’t see that they’re perfect fated match is standing right in front of them, arguing at full tilt. They don’t realize their hearts are for each other but both of them have locked up their emotions. It’ll take a deranged serial killer to bring them together.
But will solving the case give them the key to their love? Or will it be locked away forever?