Skin Collector (Death is his art) - Jeffery Deaver

A new type of serial killer is stalking the streets of New York - one more devious and disturbing than ever before. They call this butcher The Skin Collector: a tattooist with a chamber of torture hidden deep underground. But instead of using ink to create each masterpiece, the artist uses a lethal poison which will render targets dead before they can even entertain the prospect of escape... Drafted in to investigate, NYPD detective Lincoln Rhyme and his associate Amelia Sachs have little to go on but a series of cryptic messages left etched into the skin of the deceased. As the pair struggle to discover the meaning behind the designs, they are led down a treacherous and twisting path where nothing is as it seems. And with the clock rapidly ticking before the killer strikes again, they must untangle the twisted web of clues before more victims - or they themselves - are next.