Michael Jackson's personal physician Dr Conrad Murray faces up to four years in prison after he was convicted of the involuntary manslaughter of the star.
A jury of seven men and five women took eight and a half hours to reach a unanimous verdict, ruling that the doctor gave the King of Pop a fatal overdose of the anaesthetic propofol.
Murray, who could also lose his medical licence, was stony-faced as the verdict was read out. The physician was refused bail and was led away to jail in handcuffs ahead of his sentencing on November 29.
Outside Los Angeles Superior Court, fans cheered when they learned of the conviction. Some were overcome with emotion and fainted.
Members of Jackson's family wept and his mother Katherine told a reporter: "I feel better now." After leaving court, the singer's sister LaToya Jackson tweeted: "VICTORY!!!!!!" The star's father Joe told reporters: "Justice was served," and Jermaine Jackson, the singer's brother, added: "Michael is with us." His sister Rebbie Jackson said outside court: "It's not going to bring him back but I'm happy he was found guilty."
Explaining his decision to refuse bail, judge Michael Pastor said Murray had been convicted of "homicide predicated upon criminal negligence" and may pose a flight risk now he is a convicted felon. He added that Murray's "reckless conduct" posed a "demonstrable risk to the safety of the public".
Speaking after the verdict, District Attorney Steve Cooley said: "We are gratified that the jury saw the overwhelming evidence of this case led to just one conclusion: that Dr Murray was guilty of involuntary manslaughter, the death of Michael Jackson."
Dr Rosemary Leonard, resident doctor on BBC Breakfast, said it was clear that Jackson had a "really severe" addiction to prescription medication.
"A cardiologist should not be dealing with somebody who has got this degree of drug dependency," she said.
"There are thousands of people in the world who have had terrible, severe injuries - look at the servicemen in Helmand. They don't end up as drug addicts. The medical profession failed Michael Jackson, they didn't challenge him and say 'I don't care how much you pay me, you need to get this drug addiction problem sorted' and that is what should have happened."