LOS ANGELES (AP) — Michael Jackson’s doctor was convicted Monday of involuntary manslaughter after a trial that painted him as a reckless caregiver who administered a lethal dose of a powerful anesthetic that killed the pop star.

The verdict against Dr. Conrad Murray marked the latest chapter in one of pop culture’s most shocking tragedies — the death of the King of Pop on the eve of the singer’s heavily promoted comeback concerts.

The jury deliberated less than nine hours. Murray, 58, faces a sentence of up to four years in prison. He could also lose his medical license.

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Jackson died on June 25, 2009. The complete story of his death finally emerged during the six-week trial. It was the tale of a tormented genius on the brink of what might have been his greatest triumph with one impediment standing in his way — extreme insomnia.

Testimony came from medical experts, household employees and Murray’s former girlfriends, among others.

The most shocking moments, however, came when prosecutors displayed a large picture of Jackson’s gaunt, lifeless body on a hospital gurney and played the sound of his drugged, slurred voice, as recorded by Murray just weeks before the singer’s death.

Jackson talked about plans for a children’s hospital and his hope of cementing a legacy larger than that of Elvis Presley or The Beatles.

“We have to be phenomenal,” he said about his “This Is It” concerts in London. “When people leave this show, when people leave my show, I want them to say, ‘I’ve never seen nothing like this in my life. Go. Go. I’ve never seen nothing like this. Go. It’s amazing. He’s the greatest entertainer in the world.’”

Throughout the trial, Jackson family members watched from the spectator gallery, fans gathered outside with signs and T-shirts demanding, “Justice for Michael,” and an international press corps broadcast reports around the world. The trial was televised and streamed on the Internet.

Prosecutors portrayed Murray as an incompetent doctor who used the anesthetic propofol without adequate safeguards and whose neglect left Jackson abandoned as he lay dying.

Murray’s lawyers sought to show the doctor was a medical angel of mercy, with former patients vouching for his skills. Murray told police from the outset that he gave Jackson propofol and other sedatives as the star struggled for sleep to prepare for his shows. But the doctor said he administered only a small dose on the day Jackson died.

Lawyers for Murray and a defense expert blamed Jackson for his own death, saying the singer gave himself the fatal dose of propofol while Murray wasn’t watching. A prosecution expert said that theory was crazy.

Murray said he had formed a close friendship with Jackson, never meant to harm him and couldn’t explain why he died.

The circumstances of Jackson’s death at the age of 50 were as bizarre as any chapter in the superstar’s sensational life story.

Jackson was found not breathing in his own bed in his rented mansion after being dosed intravenously with propofol, a drug normally administered in hospitals during surgery.

The coroner ruled the case a homicide and the blame would fall to the last person who had seen Jackson alive — Murray, who had been hired to care for the singer as the comeback concerts neared.

Craving sleep, Jackson had searched for a doctor who would give him the intravenous anesthetic that Jackson called his “milk” and believed to be his salvation. Other medical professionals turned him down, according to trial testimony.

Murray gave up his practices in Houston and Las Vegas and agreed to travel with Jackson and work as his personal physician indefinitely.

For six weeks, as Jackson undertook strenuous rehearsals, Murray infused him with propofol every night, the doctor told police. He later tried to wean Jackson from the drug because he feared he was becoming addicted.

Jackson planned to pay Murray $150,000 a month for an extended tour in Europe. In the end, the doctor was never paid a penny because Jackson died before signing the contract.

During the last 24 hours of his life, Jackson sang and danced at a spirited rehearsal, reveling in the adulation of fans who greeted him outside. Then came a night of horror, chasing sleep — the most elusive treasure the millionaire entertainer could not buy.

Testimony showed Murray gave Jackson intravenous doses that night of the sedatives lorazepam and midazolam. Jackson also took a Valium pill. But nothing seemed to bring sleep.

Finally, Murray told police, he gave the singer a small dose of propofol — 25 milligrams — that seemed to put him to sleep. The doctor said he felt it was safe to leave his patient’s bedside for a few minutes, but Jackson was not breathing when he returned.

Witnesses said he was most likely dead at that point.

What happened next was a matter of dispute during the trial. Security and household staff described Murray as panicked, never calling emergency services but trying to give Jackson CPR on his bed instead of the firm floor.

A guard said Murray was concerned with packing up and hiding medicine bottles and IV equipment before telling him to call emergency services. Prosecutors said Murray was distracted while Jackson was sedated, citing Murray’s cell phone records to show he made numerous calls.

Authorities never accused Murray of intending to kill the star, and it took eight months for them to file the involuntary manslaughter charge against him. It was the lowest possible felony charge involving a homicide.

There was no law against administering propofol or the other sedatives. But prosecution expert witnesses said Murray was acting well below the standard of care required of a physician.

They said using propofol in a home setting without lifesaving equipment on hand was an egregious deviation from that standard. They called it gross negligence, the legal basis for an involuntary manslaughter charge.

The defense team countered with its own expert who presented calculations suggesting that Jackson gave himself the fatal dose.

In closing arguments, the prosecutor said the mystery of what happened behind the closed doors of Jackson’s bedroom on the fatal day probably would never be solved.

Copyright 2011 The Associated Press.