A convicted cocaine dealer caught selling drugs in Rockland is going to prison for seven years. 36-year-old Kaihlil Nigro of Portland was sentenced last week on two counts of aggravated trafficking in cocaine.Authorities say Nigro sold drugs to an undercover informant last August. A week later, drug agents arrested him and a local brother and sister at house in Rockland. Nigro was found with about $5,300 worth of cocaine in a safe. Skip Marriner and Jennifer Marriner told police Nigro was driving in from Portland to sell drugs in the area. They were previously sentenced to two years probation, each.