The Executioner by Chris Carter

I didn't realise when I bought it that this was the second book in the series. It didn't matter though as it was easy enough to read it as a stand alone book. It was fast paced and although slightly implausible at times it was still a great book. It starts with a decapitated priest who has a dog's head instead of his own and when the detectives discover the number 3 painted on him they realise that maybe the priest isn't the executioner's first victim. As subsequent victims are discovered it is down to Hunter and Garcia to uncover a link between them and a motive for their deaths.