Bringer of Night by Jordan L. Hawk

The vampire spirit Gray and his human host Caleb have sworn never to drink from a human again. But when a woman from one of Caleb's tour groups is murdered by what appears to be a vampire, Caleb is arrested as the prime suspect. Not only does she have a bite mark on her throat, but security camera footage reveals her murderer looks exactly like Caleb, down to the clothes he was wearing that night.

Can Caleb and Gray clear their names, not only to the police but to John? Or will the new life they've built in New Orleans come crashing down around them?