LOS ANGELES (Reuters) - A judge on Tuesday ordered Michael Jackson’s doctor to stand trial on a charge of involuntary manslaughter in the pop star’s drug overdose death and suspended the doctor’s California medical license.

Los Angeles Superior Court Judge Michael Pastor found that enough evidence exists to bring Dr. Conrad Murray to trial for the “Thriller” singer’s death in June 2009, due principally to an overdose of the powerful anesthetic propofol.

“I order the defendant be held to answer” for the crime, Pastor said after six days of testimony in a preliminary hearing as Jackson’s sister, LaToya, and his brother, Randy, looked on.

Involuntary manslaughter is defined as an unintentional killing without malice and is a lesser charge than murder. Still, Murray faces a maximum sentence of four years in prison if convicted. He has pleaded not guilty to the charge.

During the hearing, prosecutors brought to the witness stand a Jackson employee who testified that Murray ordered him to hide drug evidence the day the singer died, June 25. Phone records showed Murray called his girlfriend shortly after giving Jackson propofol, instead of caring for the singer.

Coroners ruled Jackson died from propofol and the effect of sedatives including lorazepam, but the anesthetic was the key drug. Propofol is most often used in hospitals, but Jackson took it as a sleep aid. Murray has admitted giving the singer propofol.

Defense attorneys have suggested Jackson may have injected himself with the fatal dose, but a pair of medical experts testified on Tuesday that even if that were the case, Murray was still be responsible because he supplied the propofol.

“It’s like a heroin addict -- you’re going to walk away from him with a syringe full of heroin next to him? It’s the same thing with propofol,” said Dr. Richard Ruffalo, an anesthesiologist at California’s Hoag Clinic.

MURRAY, A HELP?

Defense attorneys also claimed Murray was trying to get Jackson off drugs to help him.

“Why, all of the sudden on the day that Dr. Conrad Murray is trying to wean off Michael Jackson trying anything else but propofol, would he suddenly be given a dosage that goes above that. That defies common sense,” defense attorney Joseph Low said in his summation on Tuesday.

Low even suggested Jackson’s drug use had riddled his body and, by age 50, it may have been his time to die.

Deputy District Attorney David Walgren seized on that last point, saying: “the standard of care was breached, unfortunately and tragically, over and over again because of Dr. Murray’s actions. That is why Michael Jackson is no longer here. Not because it was Michael Jackson’s time to go.”

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Judge Pastor’s ruling largely had been expected because the burden of proof is low in a preliminary hearing. Murray is due in court on January 25, at which time a trial date could be set.

Outside the courthouse, Randy Jackson appeared pleased at the outcome. “I think the prosecutors, everyone, did a great job,” he told reporters as he was entering his car.

Michael Jackson is a member of the Jackson family of singers and is among the best-selling recording artists of all time. He died of the drug overdose only days ahead of a series of planned comeback concerts in London. Murray had been hired to care for the singer as he rehearsed for those shows.