Michael Jackson impersonator Goward Horton poses for the media outside the courthouse during the opening day of Dr. Conrad Murray's trial in the death of pop star Michael Jackson in Los Angeles September 27, 2011. [Photo/Agencies]

"Perfect storm"

"We believe the evidence will show. ... that when Dr. Murray left the room, Michael Jackson self-administered a dose of propofol that with the lorazepam created a perfect storm within his body that killed him instantly," Chernoff added.

Jackson's parents, Joe and Katherine, his sisters, Janet and La Toya, and other family members were in court on Tuesday, while outside dozens of fans outside the courtroom held sunflowers, pictures of the dead pop star, and placards saying "Justice for Michael."

Walgren opened the prosecution case by showing jurors a photo of a thin Jackson lying dead on a hospital gurney, side by side with a picture of him singing and dancing while rehearsing for the concerts one day before. Footage of the rehearsals were made into Jackson's posthumous concert movie "This Is It" in 2009, that became a global box office hit.

But Chernoff painted a different scenario, claiming that Jackson was under huge pressure to make the concerts -- his first in 10 years -- a success, not just financially but also to restore his image after his damaging 2005 trial and acquittal for child molestation.

Jurors are expected to hear testimony from the paramedics who transported Jackson to the hospital, medical experts, Jackson's choreographer and Murray's girlfriends.

The first prosecution witness is expected to be Kenny Ortega, the choreographer and film director who was hired to stage the London shows and who was conducting rehearsals with Jackson in Los Angeles.