The Guardians of the Night Series by Jenna Black

Vampires. They hunt in every major city, hidden by the crowds, shielded by disbelief. They are Killers, and their prey is human. Not all vampires are Killers. The Guardians of the Night sacrifice the superior physical and psychic strength that comes with feeding on humans to protect them.  But the Guardians walk a thin line, for even a single kill could leave them helplessly addicted to murder. When detective-turned-P.I... moreVampires. They hunt in every major city, hidden by the crowds, shielded by disbelief. They are Killers, and their prey is human. Not all vampires are Killers. The Guardians of the Night sacrifice the superior physical and psychic strength that comes with feeding on humans to protect them.  But the Guardians walk a thin line, for even a single kill could leave them helplessly addicted to murder. When detective-turned-P.I. Carolyn Mathers was left at the altar, she never once thought her fiancé had been turned into a vampire. Two years later, Gray reappears, bringing murder, mystery, and an unbelievable tale of Guardians, blood-thirsty Killers, and his own transformation with him.  And he's been accused of murder. A first-rate P.I., Carolyn is determined to help.  Gray won’t allow what he is now to taint her -- but Carolyn vows to never let him go again. But will helping Gray mean becoming a creature of the night? less

Vampires They hunt in every major city, hidden by the crowds, shielded by disbelief. They are Killers, and their prey is human. Not all vampires are Killers. The Guardians of the Night sacrifice the superior physical and psychic strength that comes with feeding on humans to protect them.  But the Guardians walk a thin line, for even a single kill could leave them helplessly addicted to murder. Jules Gerard has vowed that he will never become a Killer... moreVampires They hunt in every major city, hidden by the crowds, shielded by disbelief. They are Killers, and their prey is human. Not all vampires are Killers. The Guardians of the Night sacrifice the superior physical and psychic strength that comes with feeding on humans to protect them.  But the Guardians walk a thin line, for even a single kill could leave them helplessly addicted to murder. Jules Gerard has vowed that he will never become a Killer.  But when he discovers that the man who turned him into a vampire is dead and kicking in Baltimore, the allure of extra power is tempting. Standing in his way is a human, spitfire Hannah Moore, who has followed him to Baltimore to help him confront his past. Hannah doesn't seem to realize how dangerous vampires can be--and despite his façade of disdain, Jules has a real soft spot for the petite P.I. Jules is going to have to choose: vengeance or love? Damnation or redemption? less

The baddest of the bad boys…   Gabriel is a five hundred year old vampire with the soul of a Killer.  He has defeated his mother in a battle for the territory of Baltimore, and vowed to take vengeance upon his father, the Master of Philadelphia, for a centuries-old betrayal.   Jezebel, Gabriel's new fledgling, is a soul as scarred as his own, yet Gabriel finds that the ice around his heart slowly melts when she is near... moreThe baddest of the bad boys…   Gabriel is a five hundred year old vampire with the soul of a Killer.  He has defeated his mother in a battle for the territory of Baltimore, and vowed to take vengeance upon his father, the Master of Philadelphia, for a centuries-old betrayal.   Jezebel, Gabriel's new fledgling, is a soul as scarred as his own, yet Gabriel finds that the ice around his heart slowly melts when she is near.  But one of Gabriel's ancient enemies has targeted her--and if Gabriel wants to save her, he will have to abandon his plans for revenge and join forces with his father.   The question is not whether or not Gabriel can redeem himself from his past, but whether he can ever forgive himself… less

Drake is a Killer  vampire. Unlike the Guardians of the Night, Drake feeds on human blood, choosing victims who deserve to die.  But still he works with the Guardians to protect those humans who yet have some good in them.  When Gabriel, the leader of the Baltimore Guardians, mysteriously disappears, Drake finds himself in charge of a small band of inexperienced fledgling vampires... moreDrake is a Killer  vampire. Unlike the Guardians of the Night, Drake feeds on human blood, choosing victims who deserve to die.  But still he works with the Guardians to protect those humans who yet have some good in them.  When Gabriel, the leader of the Baltimore Guardians, mysteriously disappears, Drake finds himself in charge of a small band of inexperienced fledgling vampires.  When a delegation of European Killers arrives in Baltimore  looking for Gabriel, Drake must call on all the savagery of his sordid past to keep the Guardians in line—and to protect them from the ruthless Killers. Forced to confront a past he has tried so hard to outrun, Drake risks losing his humanity. His only hope is Faith, the French Seigneur’s concubine, who desperately needs his help to rescue her human sister from the Seigneur’s clutches.  Then someone begins killing the members of the European vampire delegation, and Drake is the only suspect. Will Drake be saved by love, or will he become a Killer without a conscience? less