The trial of Michael Jackson's doctor Conrad Murray has been postponed until Wednesday. Friday was also an off day and while the prosecution was finalizing its case, one of the final witnesses experienced a death in the family, putting everything on hold. This witness' knowledge of propofol, the surgical anesthetic that killed Jackson in June 2009, is key for the prosecution, which alleges that Murray administered the final, fatal dose and did not properly look after his care in the subsequent moments. That's why he is on trial for involuntary manslaughter.

The Associated Press reports that the proceedings will resume on Wednesday.

The trial was put on hold on Friday so that Dr. Steven Shafer, the final prosecution witness who is respected for his expertise in the areas of anesthesia and pharmacology and is expected to counter the defense's controversial claim that Jackson self-administered the dose that killed him via a leg catheter, could attend a previously scheduled anesthesiology conference in Chicago. However, while headed to the conference, Shafer's father passed away and he end up not attending as planned.

Word is the defense is backing off that "Jackson administered the propofol himself" in favor of claiming he administered lorazepam himself; lorazepam was also found in his system.

After Shafer testifies, the defense will then proceed with its case. 15 witnesses are likely to be called and the defense's case could run through Friday or as late as the following Monday.