How discarded chewing gum helped convict a serial rapist of two cold case murders

By Nina Giraldo, CNN (CNN) — Susan Logothetti and two colleagues stood outside the yellow home in Everett, Washington, donning T-shirts and holding flyers promoting a chewing gum company. Mitchell Gaff opened the door wearing pajama pants, welcomed the trio into his house and agreed to a taste test, sampling different sticks of gum with