Four years after 92-year-old Kathryn Johnston was shot and killed by Atlanta narcotics officers who falsified evidence before and after a completely unwarranted raid on her home, the city of Atlanta has announced it will pay a $4.9 million settlement to her family.  In November 2006, officers conducted a “no knock” raid on Johnston’s home based on bogus information from an informant who said he had purchased drugs there. (After the raid, the informant told a local news station that he had never even…