A Hacienda Heights physician accused of strangling and dismembering his 11-year-old son pleaded not guilty in Pomona Municipal Court and won dismissal of a “special circumstances” allegation, which would have made him subject to the death penalty. But it was only a first-round victory for Dr. Khalid Parwez, 38, an obstetrician and gynecologist. The prosecutor, Deputy Dist. Atty. Richard D. Burns III, said after the hearing that he will fight in higher court to seek either death or life imprisonment for Parwez.