TRENTON, N.J. — A federal judge whose son was slain at their home by an attorney who had stalked her invoked his memory Friday at the signing of a New Jersey law aimed at protecting judges’ personal information from being publicly accessible.“With today’s bill signing, I believe, symbolically, Daniel is doing what he did for his father and I — he is protecting the lives of countless judicial officers,” U.S. District Judge Esther Salas said as she choked back tears.Twenty-year-old Daniel …