What makes a person not only murder, but murder multiple people over days, weeks and even years? There's a special name for these types of murderers: serial killers.
"I’ve found that many a holiday has been enhanced when on the trail of a favourite novel. There’s something memorable about standing in the shoes of your favourite characters and seeing at first-hand the scenes of best-loved stories." via The Island Review http://theislandreview.com/content/scotland-crime-fiction-islands