By ANDREW WELSH-HUGGINS and JOHN SEEWER COLUMBUS, Ohio (AP) — The man who gunned down nine people in Dayton, Ohio, two years ago had fantasized about mass shootings, serial killings and murder-suicide for at least a decade before carrying out the Aug. 4, 2019, attack, the FBI said Monday as it announced the conclusion of its investigation. Shooter Connor Betts didn't share specific details with friends