Defenders Against Death Penalty Construct Cases for Compassion
Article examines workings of New York State's Capital Defender Office, established more than year ago to oversee representation of most of defendants who may face death penalty; unlike traditional criminal defense, which looks for fractures in prosecution's case, capital defenders must look beyond nightmarish crime; must ferret out nightmarish history of criminal and turn over much of life history to prosecutors, offering preview of what lawyers will present to jurors at sentencing phase of trial; some cases handled by Capital Defender Office and their outcomes discussed; photos (M)