Investigators want to know why a Manchester resident drove to the Canadian border and allegedly shot at a U.S. Border Patrol agent in Pittsburg, N.H. U.S. Attorney Erin Creegan wants to know if there are any connections between the nonbinary suspect and the so-called “Zizian” group, which has been linked to the fatal shooting of a Border Patrol agent near the Vermont-Canada border last year. And members of law enforcement and the general public …