Michael Jackson's personal doctor was found guilty on Monday of involuntary manslaughter in the pop star's drug-related death in 2009 but may not spend much time in jail.

Dr. Conrad Murray, 58, was led away in handcuffs after the jury in Los Angeles reached a unanimous verdict. Dozens of fans outside the court erupted in cheers and some burst into tears.

"Justice was served. Michael is with us," said Jackson's brother Jermaine.

Murray faces up to four years behind bars when he is sentenced on November 29th but may spend only months in Los Angeles' overcrowded cells.

Murray pleaded not guilty to giving the "Thriller" singer a fatal dose of the powerful anesthetic propofol - normally used in surgery - that was ruled the main cause of his death at the age of 50.

Prosecutors argued Murray was grossly negligent in administering the propofol to help Jackson sleep. Defense lawyers claimed Jackson delivered the fatal dose to himself.

The judge ordered Murray, who had been free on bail for two years, held in custody until his sentencing. The doctor did not testify at the six-week trial and looked impassive as the guilty verdict was announced in the packed courtroom.

Jackson's mother Katherine and sister Rebbie cried silently at the result. Other family members in court included his siblings La Toya and Randy, along with his father Joe.

"I am," Katherine Jackson said when reporters asked if she was pleased with the verdict.

Jackson was found lifeless at his Los Angeles mansion on June 25, 2009.

Murray admitted giving the singer a small dose of propofol to help him sleep. But his lawyers argued the singer was dependent on the drug and likely gave himself an extra, fatal dose - and swallowed a handful of sedatives - without Murray knowing.

But prosecutors said Murray was negligent for administering the drug in a home setting, failing to monitor Jackson, delaying a call to emergency services and failing to tell medical personnel he gave the singer propofol.

Judge Michael Pastor said Murray was "now a convicted felon who has been deemed the causative factor in Michael Jackson's death."

Pastor said the doctor should be detained before being sentenced to protect public safety.