Linda Deutsch, AP

The lawyer for Michael Jackson's doctor says there will be no plea bargain in the involuntary manslaughter case, though he worries whether an impartial jury can be seated for a trial in the death of one of the world's most famous entertainers. The case against Dr. Conrad Murray is complicated, involving drugs, dosages, medical protocols and other complex issues. Defense lawyers and prosecutors are crafting their legal strategies ahead of a summertime preliminary hearing where much of the evidence may become public.

Already, potentially damaging information about Murray has been revealed. An autopsy report found Jackson died from an overdose of the powerful anesthetic propofol. In a statement to police, Murray acknowledged giving Jackson the drug and other sedatives to help him sleep, then briefly leaving his bedside. Cellular phone records show he made at least three personal calls around the time Jackson was stricken.

A Jackson employee who said he was in the room while Murray worked to save the pop star told police the doctor interrupted CPR to collect drug vials. Murray maintains his innocence, and his lawyer, Ed Chernoff, has said nothing that he gave Jackson should have killed him. Chernoff noted the Jackson employee gave a different version of events to police in another statement.

“You may find after you are done watching the trial that it is not nearly as cut and dried as has been presented,” Chernoff told The Associated Press. “One thing that simply will never be the truth is that Dr. Murray pumped a bunch of drugs into Michael Jackson and walked out of that room. He's not that kind of guy.”

Murray, a 57-year-old cardiologist with practices in Houston and Las Vegas, was hired by the superstar to look after his health during rigorous rehearsals, and planned to accompany Jackson to London. Deputy District Attorney David Walgren will seek to prove the doctor acted with gross negligence when he gave the singer propofol to help him sleep.

The anesthetic is supposed to be used in hospital situations for surgery and patients are to be monitored constantly by anesthesia professionals. The drug's effects are intensified when used in conjunction with other sedatives.

TMZ has reported that among the defense strategies being discussed is the possibility Jackson administered the fatal dose himself. Chernoff declined to discuss how he might defend Murray and said a final decision won't be made until he hears the prosecution's theory at the preliminary hearing. Regardless of what prosecutors present, he said there will be no plea bargain.

“The district attorney didn't overcharge the case,” said celebrity attorney Harland Braun. “"They are charging what they think they can prove.” Murray already is deeply in debt and pleading to a felony would open him to liability in a civil damages trial. The Jackson family has spoken of suing Murray for wrongful death.

To gain a conviction at trial, prosecutors will have to walk jurors through Jackson's complicated medical history as well as the events leading up to his death.