Dr. Paul White, an expert in the anesthetic propofol, will finally lay out his rationale for the defense theory that Jackson somehow gave himself a fatal dose of the drug when his doctor left the room.
White's testimony will likely be vigorously challenged by prosecutors, who spent four weeks laying out their case that Dr. Conrad Murray is a greedy, inept and reckless doctor who was giving Jackson propofol as a sleep aid. But cross-examination of White will be delayed until Monday to give prosecutors more time to review a new analysis prepared by the defense based on recently-conducted tests on samples taken during Jackson's autopsy.
"This is the entire crux of the defense case," Deputy District Attorney David Walgren said in arguing for a delay.
The judge hearing the case, which ends its fifth week on Friday, reluctantly agreed to delay the cross examination and said he is concerned about losing jurors. Superior Court Judge Michael Pastor however noted that the panel of has remained rapt throughout the trial.
"Every single member of that jury and all the alternates are paying extraordinary attention to every witness," Pastor said.
Murray has pleaded not guilty.
White's opinions will challenge those of the prosecution's main expert, Dr. Steven Shafer, who testified that the only scenario he believes explains Jackson's death is that Murray placed Jackson on an IV drip and left the room after he thought the singer was sleeping peacefully.
Murray told police he left Jackson's bedside, but claims he only gave the singer a small dose of propofol the morning of Jackson's death. He said he left the room and returned after two minutes to find the pop superstar unresponsive.
Murray's defense attorneys have repeatedly claimed that Jackson somehow gave himself the fatal dose, but it will be up to White to explain how that would be possible.
Defense attorney J. Michael Flanagan said that the new models White will show jurors on Friday will offer different simulations about the drugs propofol and sedative lorazepam. They are based on a new computer program and updated test results.
Flanagan did not reveal what conclusions White drew from the new models, or whether they would change his testimony.
White is a retired researcher and professor who performed clinical studies of propofol for years before it was approved for usage by the Food and Drug Administration in 1989. He said he was initially reluctant to become involved in the case, but after reading through more than a dozen expert reports, he couldn't figure out how others came to the conclusion that Murray would have had to leave Jackson on a propofol IV drip for the singer to have died with the anesthetic still coursing through his body.
He said the others' theories didn't make sense based on Murray's statement to police.
"I thought that there were questions if in fact Murray had administered the drugs that he described in his conversations with the police department in the doses he described, I would not have expected Michael Jackson to have died," White said.
He continued to work on the case after meeting with Murray, although White was not allowed to testify about his conversations with the Houston-based cardiologist.
Flanagan early in White's testimony on Thursday asked the doctor to address "the elephant in the room" -- whether he could justify Murray's actions if he left Jackson hooked to a propofol IV and then left the room.
"Absolutely not," White replied.