Los Angeles , California ( CNN ) -- None of the seven doctors and one nurse investigated by California authorities will face criminal prosecution in the death of singer Michael Jackson , the state attorney general 's office said Wednesday . Investigators did not find sufficient evidence to recommend criminal prosecution of any of the medical practitioners , said Christine Gasparac , a spokeswoman for Attorney General Jerry Brown . But a doctor who prescribed drugs to the pop singer using a fake name shortly before the singer 's death could be disciplined by the California medical board , Gasparac said . She would not identify the doctor referred to the medical board or the others who were cleared . Dr. Conrad Murray , who was Jackson 's personal physician when he died a year ago , was not part of the probe , Gasparac said . Murray was charged with involuntary manslaughter earlier this year in the entertainer 's death . State drug agents executed search warrants at several doctors ' offices last summer and at least one pharmacy . `` After reviewing hundreds of pages of records and documents obtained from the medical practitioners , the attorney general 's office has referred one doctor , who wrote prescriptions to an alias known to have been used by Jackson , to the California medical board for further review , '' Gasparac said . Agents spent several hours inside the Mickey Fine Pharmacy just below the Beverly Hills practice of Dr. Arnold Klein , Jackson 's dermatologist . Investigators also visited Klein 's office , where Jackson was seen several times in the weeks before his June 25 , 2009 , death . Klein told CNN last year that he never prescribed dangerous drugs to the singer . Searches of Jackson 's rented mansion revealed a long list of prescription drugs in his bedroom after his death , according to court documents and the autopsy report . The Los Angeles County coroner ruled that Jackson 's death was from an overdose of propofol , a powerful anesthesia used to put surgical patients to sleep . A consultant 's report included in the autopsy said the level of lorazepam , a powerful anti-anxiety agent found in Jackson 's body `` would have accentuated the respiratory and cardiovascular depression from propofol . '' CNN 's Carey Bodenheimer contributed to this report .
LAPD asks state drug agents to probe seven Jackson doctors , one nurse . One doctor referred to medical board . May 19, 2009 - Los Angeles Times reports that the California Medical Board has opened an investigation into Dr. Michael Jackson's personal physician and a former nurse. No evidence to support criminal prosecution . Dr. Conrad Murray already faces a criminal charge .