From reading accounts about the dozens of Texans involved with/knew of - including at least 5 who suicided themselves right afterwards - it seems Mac Wallace, who seemed to have hit at least 5 for LBJ over the years personally, set up the snipers’ nest, E.L. Hunt got the SS to modify the route AND provide an agent in case LHO missed and another backup on the grassy knoll. Three levels of surety after Hunt learned through his (ex-FBIer staffed) private intel which Hoover helped build, since JEH and virtually all Texans viewed JFK as a commie. Only Q is which bullet made target.
s/b after Hunt learned early that Wallace was going to announce.