The man who killed nine people in Dayton’s Oregon District was seen carrying a gun and protesting against the Ku Klux Klan at a rally downtown in May. Connor Betts, 24, was shot and killed by Dayton police during the Sunday morning rampage. Neither the police nor the FBI have identified a motive for the attack, though the federal authorities said Tuesday he “was exploring violent ideologies” before the shooting. MORE:Dayton Shooting: Former bandmate, ex-girlfriend cut ties with Betts before mass shooting The May 25 rally attracted about 500 to 600 counter-protesters who opposed the nine Klansman who came from...