The Covenant by Evangeline Anderson
Kaitlyn Richards is a witch with powers beyond the norm. Her unique abilities make her one of the few people in the state of Florida qualified to be an S.E., or Supernatural Enforcer. As part of her duties she uses her home as a magical holding cell for creatures too strong to be contained in normal human jails.
Holden Sumner is a three-hundred-year-old vampire on a mission-he's been stalking a serial-killing demon for centuries and he needs Kaitlyn's help to kill it. The problem is, she won't give him the time of night. But Sumner is determined to get under her skin.
Though Kaitlyn is reluctant to get involved with a vampire, she agrees to help Sumner search for the killer. But in order to drive the demon back to hell and stop the slaughter of innocents, she will have to bind herself more tightly than she ever thought possible to a man she doesn't want to love.
She and Sumner must form a blood covenant...or die trying.