LOS ANGELES — Michael Jackson's mother and siblings appeared in court Tuesday to hear testimony accusing a doctor of killing the pop icon by administering an overdose of powerful sedative drugs.

Katherine Jackson, his sister LaToya and brother Jackie turned up for a pre-trial hearing into the role of Dr. Conrad Murray, charged with involuntary manslaughter over the singer's shock June 2009 death.

His father Joe Jackson, while not here for the start of the expected two-week hearing, was cited as dismissing claims that the King of Pop killed himself by self-administering the drugs.

"He's a Jackson. He doesn't think like that. One month before he died he told Katherine THEY were going to kill him for his publishing catalog," he told the X17online.com celebrity news website, without saying who "they" were.

"He said THEY were going to kill him. Why would he kill himself?" added Joe Jackson, who X17online said was in Las Vegas.

The hearing began with LA deputy district attorney David Walgren setting out the prosecution case against Murray, who he said gave Jackson the powerful sedative propofol every night for nearly two months.

On the day Jackson died Murray allegedly failed to act professionally in a number of ways, including not using proper medical equipment, not calling 911 within a reasonable time, and failing to tell paramedics about Jackson's condition.

"In the opinion of our medical experts they will show an extreme deviation from expected standard of care," he told the court, before Jackson's choreographer Kenny Ortega was called to testify.

It was unclear whether any of the Jackson family would testify at the hearings in the Los Angeles Superior Court, or simply watch the proceedings. Murray avoided the press by arriving in court via an underground parking lot.

At the preliminary hearing, Los Angeles Superior Court Judge Michael Pastor will decide whether there is enough evidence to try Murray, 57, on charges of involuntary manslaughter -- essentially, a killing done without malice.

Murray, a cardiologist, is accused of administering a potent cocktail of sedatives and painkillers to help Jackson sleep. He has pleaded not guilty to the charges.

Jackson, the biggest pop star of his generation, died at age 50 from drug-induced respiratory arrest on June 25, 2009.

His demise shocked the entertainment world and triggered intense debate over the performer's health in the run up to a series of comeback concerts in London.

Walgren claimed last week that defense lawyers will say Jackson woke up that fateful night at his Beverly Hills mansion and injected himself with an overdose while Murray was out of the room.

"I do think it's clear the defense is operating under the theory that the victim, Michael Jackson, killed himself," he said at a preliminary hearing last week.

There is likely to be strong emphasis in the hearing on Murray's use of propofol, an anesthetic used in surgery, to treat Jackson's insomnia. The powerful drug is not approved for home use or to treat sleep disorders.

A preliminary hearing is usually a routine procedure in which only one or two witnesses are called, but prosecutors are set to call as many as 35 witnesses, according to the Los Angeles Times.

In a separate legal action, Joe Jackson is seeking unspecified damages from Murray and others, including a Las Vegas pharmacy said to have supplied the propofol administered to the singer before he died.