RIVERHEAD, N.Y. (AP) — A Long Island architect accused in a string of long-unsolved slayings known as the Gilgo Beach killings is expected to plead guilty on Wednesday, closing a case that bedeviled investigators, agonized victims’ relatives and tantalized a true-crime obsessed public for years. Rex Heuermann, 62, is charged with murdering seven women, many of them sex workers, over a 17-year span. A guilty plea would put him in prison for the rest of his life.