Live Blog: Trial Of Michael Jackson's Doctor

The defence has begun its case in the trial of Michael Jackson's doctor after the last prosecution witness finished giving evidence.

Defence lawyers are set to call 15 witnesses as they fight the involuntary manslaughter charge against Conrad Murray.

The prosecution case lasted nearly four weeks and prosecutors called 33 witnesses.

Coroner officials said the 50-year-old pop star died from an overdose of the anaesthetic propofol.

The final prosecution witness, Dr Steven Shafer, said the only possible explanation for the death based on the evidence was that Murray put the singer on an intravenous drip of propofol then left Jackson's bedroom after he appeared to be asleep.

Murray, 58, faces up to four years in jail if convicted over the singer's death in June 2009.

Prosecutors claim Murray gave Jackson an overdose of the anaesthetic - which he was using as a sedative to treat Jackson's insomnia - and abandoned his patient at the crucial moment.

He admits administering propofol to the pop star but denies involuntary manslaughter.

The defendant's lawyers say Jackson, desperate to get to sleep to be ready for rehearsals for a planned series of comeback concerts in London, gave himself an extra, fatal dose of the drug when Murray was out of the room.

Among the first defence witnesses was Allan Metzger who was a doctor to Jackson.

He told jurors that Jackson asked him about intravenous sleep medications about two months before the star's death.

Dr Metzger said he knew Jackson had difficulty sleeping for at least 15 years before Jackson died.

He told the trial he did not provide Jackson with any IV medication, and that he warned the singer that IV anaesthetics should never be administered outside a hospital setting.

Dan Myers and Orlando Martinez - two Los Angeles police detectives who worked on the Jackson case - were also called by the defence.

Defence lawyer Nareg Gourjian asked both about statements given by Jackson's bodyguard Alberto Alvarez, who previously testified Murray told him to place some medical equipment and vials in a bag before calling 911.

The defence has contended that Alvarez may have changed his story to fit details released by coroner's officials.

The lawyers also noted previously that the bodyguard did not mention that Murray told him to place the items in a bag until more than two months after Jackson's death.

The first witness called by the defence was Dona Norris from the Beverly Hills police department.

She answered questions about the 911 call for an ambulance made from Jackson's mansion at 12:20pm on the day of the star's death.

The defence also called a police surveillance specialist, Alexander Supall, who retrieved grainy CCTV footage of Jackson's convoy arriving home around 12:50am after a rehearsal.

The pictures were shown to the jury.

Reports suggest that the defence could complete its case by the end of the week, when the jury could retire to consider its verdict.

Earlier in the day, Dr Shafer, an expert on propofol, told the court it was difficult to know the precise effects of the drug on the pop star.

Dr Shafer said this was because the singer had been given so much propofol in the months before he died in June 2009.

The prosecution witness made his remarks during cross-examination at the trial.

Lead defence lawyer Ed Chernoff questioned Dr Shafer about mathematical models that show the risk of a patient's breathing stopping comes in the first few minutes after propofol is administered.

Dr Shafer agreed, but said it was hard to know exactly how propofol affected Jackson because he had other sedatives in his system and because he had been receiving propofol on a nightly basis for more than two months.

The anaesthesiologist said: "In Mr Jackson's case, it's harder to have that certainty.

"There's very little, almost no precedent for this level of propofol exposure."

He told the jury Murray never should have given Jackson propofol as a sleep aid at home and called Murray's treatment a "pharmacological 'Never-Never Land'".

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