To Kill a Mocking Dog — Angela Cowan

Meet Marty Hollis. His death just got a whole lot worse. Marty Hollis is a serial killer. He murdered nine people. He was hoping to make double figures, but his own death intervened. The mysterious Mr. Scarlet offers Marty the chance to live again, only now he must travel back in time and save someone's life. Marty decides to accept the challenge. Then he meets his new partner: Weedgie, a Scottish dog with attitude. It was irritation at first sight. And so Marty and Weedgie step into the swirling blackness to begin their first mission together. But Marty has a dastardly plan of his own... A Marty & Weedgie Mystery #1