Chapin Judge Criticizes Pretrial Publicity on Dean
Fed Judge Gerhard A Gesell mildly scolds special Watergate prosecutor Leon Jaworski for saying on TV program that he saw no reason to doubt veracity of John W Dean 3d, who is scheduled to testify for defense in perjury trial of Dwight L Chapin; Chapin's atty Jacob A Stein charges Jaworski's statement threw 'full weight' of prosecutor's office behind Dean; explains that he is seeking tape recording of Pres conversation with Dean in which Chapin was not mentioned to 'explore Dean's mind'; judge holds closed hearing on Stein's motion to have Dean dismissed because of atty-client relationship between Dean and Chapin while 2 were in White House; Gesell, Jaworski and Chapin illus (M)