Los Angeles police say they will not decide whether to prosecute Michael Jackson's doctor, Conrad Murray, until next year. Jackson's death last June was ruled a homicide by the county cororner, who found lethal levels of the drug propofol in the singer's body. Murray admitted to giving Jackson the drug at bedtime to help his patient sleep. But authorities have not determined whether the doctor was solely responsible, and whether there was any negligence that can be considered criminal. According to a search warrant unsealed Friday, Murray was not the first doctor to give Jackson propofol, which Jackson called his "milk." Jackson had several doctors (both local and overseas) who kept him supplied.