Dr. Conrad Murray, the personal physician of pop star Michael Jackson, sits in court during his arraignment on a charge of involuntary manslaughter in Jackson's death, in Los Angeles, California in this January 25, 2011 file photo. Jackson's dermatologist will not testify in the trial of Murray, a judge ruled on August 29, 2011, in a blow to defense plans to portray the singer as a drug addict who may have given himself the substance that caused his death.