Bestselling author Patricia Cornwell’s books are known for their authenticity, vivid storytelling, cutting-edge science and unforgettable characters.Speaking of unforgettable, forensic whiz Kay Scarpetta returns in Dust, the 21st installment of the uber-popular series. She’s the chief medical examiner and director of the Cambridge Forensic Center in Cambridge, Mass. She’s just finished working the mass shooting at Sandy Hook Elementary School in Newtown, Conn., which left her “exhausted and shaken.”But there’s no rest for Scarpetta.