In the small crowded Los Angeles courtroom, 6-foot-5 Dr. Conrad Murray is an imposing figure. Another imposing figure will loom over the room on Tuesday: The persona of Michael Jackson, the man he is accused of killing.

One of the most famous pop stars of all time will be present in the words of those who knew him, in snippets of video and in the faces of his famous family watching from the courtroom gallery.

The somber-faced Murray has said little in public, except that he most definitely did not cause Jackson’s death.

“Your honor, I am an innocent man,” Murray said quietly at his arraignment last January. “I definitely plead not guilty.”

Murray, 58, is charged with involuntary manslaughter, could face four years in prison and lose his medical license.

Prosecutors will portray him as a greedy, incompetent doctor with a messy personal life who signed on as Jackson’s personal physician for $150,000 a month to save himself from financial ruin. The defense says he was Jackson’s friend, a capable protector of the singer’s health, prepared to travel with him to Europe on his tour, and is still mourning the death.

One of Murray’s greatest assets may be what prosecutors say he wasn’t good at: Being a doctor.

“Jurors generally believe doctors,” said attorney Harland Braun, who has defended many doctors in court. “They have had to trust doctors over a lifetime. What the defense has to do is wrap him in the general feeling that doctors are good people. They care about their patients and he was not indifferent to Michael’s welfare.”

When the trial starts, Jacksons’ family will sit in a row in the courtroom. They wanted Murray charged with murder.

Edward Chernoff, the lead defense lawyer, said Murray feels the pressure.

“He feels like David in the David and Goliath story but he doesn’t have a slingshot because of the rulings that took his slingshot away,” said Chernoff, reacting last month to decisions barring chunks of evidence the defense wanted to present about Jackson’s history of drug use.

Superior Court Judge Michael Pastor, who is presiding over the trial, has since instructed lawyers to refrain from commenting on his rulings.

While witnesses will come and go, Chernoff is aware that the superstar’s shadow will be hanging over the trial. He’s concerned too about the fans who have demonized Murray and are expected to demonstrate outside the courthouse.

“If they love Michael Jackson, what do they think Michael would say about all this?” he asked. “I think he would say, ‘Leave the man alone.’ And that’s one of the reasons they love Michael.”

Following opening statements by both sides, the first prosecution witness, choreographer and director Kenny Ortega, will take jurors into Jackson’s life during the crucial weeks he was rehearsing for his landmark “This Is It” concert. Video clips from the posthumous rehearsal film could be included in his testimony.

Will Murray testify in his own defense? Nobody is saying. Although considered a dangerous strategy, it might be the only way for him to show jurors his personality.

Murray told his story in a three-hour interview with police two days after Jackson’s death but the transcript remains sealed. Early on, he posted a short video on YouTube saying, “I have done all I can do. I told the truth, and I have faith the truth will prevail.”

The truth, in one way or another, involves the drug propofol, which caused Jackson’s death. Prosecutors say Murray was grossly negligent in administering the hospital drug in a private home. Defense lawyers will try to prove that Jackson caused his own death by drinking a dose when Murray was out of the …..