WHO KILLED SHIRLEY ELIZABETH WHITTEN, ROGER DALE HIGGINS & MISS PANASOFKEE?

According to https://www.websleuths.com/forums/threads/fl-shirley-elizabeth-whitten-19-and-roger-dale-higgins-26-oak-grove-cemetery-22-february-1972.553787/ and to https: //www.reddit.com/r/UnresolvedMysteries/comments/y8vggo/shirley_elizabeth_whitten_and_roger_dale_higgins/ , Shirley Elizabeth Whitten and Roger Dale Higgins were killed on February 22, 1972 in Oak Grove Cemetery at 2027 Co Rd 232 in Woodland, Sumter County, which borders Marion County in Florida. The 2 had met the same morning, when the truck driver Roger had gone with