Three people were killed Thursday morning in a shooting in Harford County, Maryland, according to a law enforcement official.  The law enforcement official had knowledge of the shooting but wasn’t authorized to discuss details by name and spoke on condition of anonymity to The Associated Press.     The Harford County Sheriff’s Office tweeted that the shooting involved “multiple victims”.   In a tweet, Maryland Gov. Larry Hogan said his office is monitoring the situation in Aberdeen and that the state stands ready to offer any support.