L.A. County Coroner’s officials found "lethal levels" of the anesthetic propofol when they examined Michael Jackson's body, according to a search warrant just unsealed today, and have declared the death a homicide. Jackson's doctor, Conrad Murray, was treating the pop star for insomnia with the drug, the search warrant said, and gave him 25 mg of propofol on the day he died after Jackson repeatedly demanded it. Murray said he then left to make phone calls and returned to find Jackson not breathing. Investigators are focusing on whether Murray's use of propofol—a drug typically reserved for surgeries—as a sleeping aid was negligent enough to merit an involuntary manslaughter charge. The fact that the death is now ruled a homicide makes it more likely Murray will face charges.