But the sources agreed that the probe may end without criminal charges directly related to the death. Even if the coroner declares the case a homicide, authorities may not pursue charges, said one source familiar with the investigation.
"There are plenty of homicides where . . . no one is accused of murder or manslaughter," that official said, adding that Jackson's well-documented battles with prescription drug abuse would be a strong defense to any charges. Jackson's doctors may face charges for using fake names on prescriptions, a violation of state and federal laws, or for illegally furnishing the performer with medication -- as in the case pending against doctors for model Anna Nicole Smith.
That investigation took two years to build into a criminal case.
"Nothing will happen quickly," said one police official, who like others working on the case demanded anonymity because he is not authorized to speak publicly.
The law enforcement investigation of Jackson's death began soon after the singer stopped breathing in a bedroom of his rented Holmby Hills mansion June 25. LAPD detectives quickly announced that his personal physician, Dr. Conrad Murray, who was in the home at the time of Jackson's death, was wanted for questioning.
During a three-hour interview with detectives the following day, Murray described in detail his treatment of the singer. In public statements later, Murray's attorney said that the physician gave no medication that "should have" caused his death and that he was just as mystified as everyone else at the pop star's sudden death. The attorney subsequently refused to answer media inquiries about the propofol found in Jackson's home.
After autopsy results were inconclusive, the coroner's office ordered the toxicology screening. Jackson's struggles with addiction to Demerol and other prescription drugs date to the early 1990s, and at the time of his death he had prescriptions for multiple medications, including at least one prescribed using the pseudonym Omar Arnold, according to officials with knowledge of the investigation.
Coroner's officials served subpoenas on several of Jackson's physicians. Those told to submit "any and all" of Jackson's medical files and radiology and psychiatric records include Dr. Arnold Klein, a Beverly Hills dermatologist who counted Jackson among his celebrity clientele for more than two decades. Klein's lawyer met with investigators last week and emerged saying his client was not accused of wrongdoing.
