A jury of seven men and five women will be sworn in at Los Angeles' Superior Court to decide Murray's fate on involuntary manslaughter charges over the star's death on June 25, 2009.
Murray, 58, faces up to four years in jail if convicted at the twice-delayed trial, expected to last five weeks.
Murray is accused of giving Jackson an overdose of the powerful sedative propofol to help alleviate his insomnia at a rented estate in the posh Holmby
Hills neighborhood while rehearsing for a series of London comeback shows.
The doctor has never denied administering the drug -- typically used as an anesthetic during surgery -- to Jackson, but denies having "abandoned his patient" at the fatal moment.
His lawyer Ed Chernoff is expected to argue that the world-famous "Thriller" singer, desperate for sleep, administered more of the drug himself while Murray was out of the room.
The trial will be televised live, but judge Michael Pastor has stressed that jurors cannot be recorded in any way. He has rejected a defense request for them to be sequestered, as took place during the O.J. Simpson trial.
Security will be ratchet-tight at the court in downtown Los Angeles, where a major media circus is expected to be joined by often colorful Jackson supporters lamenting the star's demise and demanding justice.
Some fans complain that Grenada-born Murray, who was being paid $150,000 a month by Jackson at the time of his death, faces only four years in jail. He has been free on $75,000 bail since being charged in February 2010.
"I believe the trial is going to be a big disappointment no matter what the outcome is," said Wesley Noorhoff, head of the Legendary Michael Jackson Fan Association, which has members in over 180 countries.
The jurors include high school graduates, some with a college education and one with an MBA. Six substitute jurors were chosen in case any of the first 12 selected drop out.
Half are Jackson fans -- one of those selected, a 54-year-old woman, wrote that she "loved his music as a very young girl, as an adult not so much," while a man of the same age said he thought Jackson was a "gifted performer."
The trial was originally due in March, but was delayed twice. In that time the judge has rejected a string of requests, notably to let Jackson's former doctors testify, in what the defense hoped would prove he was a drug addict.
On the eve of the trial the judge ruled that footage of Jackson the London comeback shows cannot be shown in court.
Murray's defense lawyers claimed the footage showed Jackson already under the influence of drugs -- by implication out of control -- while prosecutors said the footage was "absolutely irrelevant."
Jackson's family is expected in court -- his mother and father, Katherine and Joe Jackson, as several of his siblings who attended six days of pre-trial hearings in January.
But simmering tensions between them were stirred in July, when Katherine Jackson announced a tribute concert for her son, scheduled in Britain on October 8, a couple of weeks into the trial.
Two of her sons, Randy and Jermaine, immediately criticized the plans as "inappropriate" and an "ill-timed event" during the LA trial of their brother's doctor. (AFP)
