Attorneys on both sides of Jackson's wrongful death lawsuit point to medical records and doctor testimony that portray his struggle with Demerol.
But jurors have seen fewer records noting Jackson's use of the substance that killed him, the anesthesia propofol.
On Wednesday, UCLA dental anesthesiologist Dr. Christine Quinn testified that she administered propofol to Jackson 10 times for dental procedures. Then in 2000, she said Jackson asked for it by name, but this time for insomnia.
Quinn told the jury Jackson said he had it before and it was the best sleep he ever had. She testified she told him that it was inappropriate for insomnia and turned him down.
The defense for AEG says the incident is one of several that show Jackson as a doctor shopper, going to whoever might provide him what he wanted and not telling physicians that he was getting simultaneous treatment from other doctors.
Katherine Jackson is suing AEG, claiming that the company should have known that the pop icon was vulnerable to dependency and should have watched his doctor closer.
Conrad Murray gave Jackson nightly infusions of propofol and Jackson's home for nearly two months.
"I think the evidence is clear that for the last two months of Michael Jackson's life, lay people that were working with him, that were employed by AEG, continued to sound the alarm that his health was deteriorating, that he was skin and bones. So I think they were on alert. They knew and they chose to ignore it," said Jackson attorney Brian Panish.
The AEG defense says Jackson's practice at hiding his use of Demerol made him even more skilled in concealing his quest for propofol.
"Even if you had some idea, as one could from the early '90s, that Mr. Jackson had an issue with opiates, none of that could lead you to have any understanding that behind closed doors that were locked with security late at night, he was taking a hospital grade anesthetic to sleep," said defense attorney Marvin Putnam.
And now jurors hear from Cherilyn Lee, who testified for prosecutors against Murray. The nurse and holistic medicine specialist testified that she, too, lectured Jackson just two months before his propofol overdose, but that Jackson said the sedation was safe as long as a doctor was monitoring him. She returns to the stand on Thursday.