Black and Blue (Inspector Rebus #8) by Ian Rankin

Bible John killed three women, and took three souvenirs. Johnny Bible killed to steal his namesake's glory.
Oilman Allan Mitchelson died for his principles. And convict Lenny Spaven died just to prove a point.
"Bible John" terrorized Glasgow in the sixties and seventies, murdering three women he met in a local ballroom--and he was never caught.
Now a copycat is at work. Nicknamed "Bible Johnny" by the media, he is a new menace with violent ambitions.