More than 19 months after Michael Jackson's shocking death at the age of 50, the only person charged in the case, the singer's former personal physician Dr. Conrad Murray, is due in court next week. And, according to a Reuters report, Murray's lawyers plan to defend Murray against a charge of involuntary manslaughter by claiming that the pop icon killed himself when he self-administered a large dose of propofol, a surgical anesthetic Jackson used as a sleep aid to combat chronic insomnia.

Murray has pleaded not guilty to a felony charge of involuntary manslaughter and has admitted to giving Jackson propofol. Murray's lawyers have said the physician did not administer any drugs that "should have" caused Jackson's death. The investigation into his death was lengthy, lasting more than eight months, after which Los Angeles prosecutors charged that Murray gave the King of Pop a lethal combination of propofol and other painkillers and sedatives in the hours before the singer was found dead in his rented Los Angeles mansion on June 25, 2009. Murray faces up to four years in prison if convicted.

Reuters reported that in a Wednesday court session to discuss evidence in the case against Murray, Los Angeles Deputy District Attorney David Walgren said he thinks that the doctor's attorneys appear to be preparing a defense claiming that Jackson self-administered the lethal dose while Murray was out of the room.

Murray's attorney would not respond to questions about Walgren's statements. Murray's trial is slated to begin on January 4 with a preliminary hearing that will determine if there is enough evidence to proceed to a full trial. Prosecutors and defense attorneys said they expect the preliminary hearing to take around two weeks.