"It's abnormal," he said from Chicago a day after visiting the Jackson family. "We don't know what happened. Was he injected, and with what? All reasonable doubt should be addressed."

People close to Michael Jackson have said since his death that they were concerned about the superstar's use of painkillers. Los Angeles County medical examiners completed an autopsy Friday and said Jackson had taken prescription medication.

Medical officials also said there was no indication of trauma or foul play. An official cause of death could take weeks.

The coroner's office released the body to Jackson's family Friday night. There was no immediate word on whether the second autopsy was being performed right away. Jesse Jackson described the family as grief-stricken.

"They're hurt because they lost a son. But the wound is now being kept open by the mystery and unanswered questions of the cause of death," he said.

Two days after Jackson died at a Los Angeles hospital, his most-famous sister, Janet, arrived at the mansion Jackson had been renting. She drove up in a Bentley and left without addressing reporters.

Moving vans also showed up at the Jackson home, leaving about an hour later. There was no indication what they might have taken away.

There was also no word from the Jackson family on funeral plans. Many of Jackson's relatives have gathered at the family's Encino compound, caring for Jackson's three children.

A person close to the family told the Associated Press that they felt upset and angry about a lack of information about those who were around the pop superstar in his final days. The person requested anonymity because of the delicate nature of the situation.

Jackson had been rehearsing for 50 London concerts aimed at restoring his crown as the "King of Pop." He died Thursday at age 50 after what his family said appeared to be cardiac arrest.

A 911 call from Jackson's rented home reported that his personal doctor was trying to revive him without success. Police have talked to the cardiologist, Conrad Murray, and have said they intended to speak with him again, but they stressed that he was not a criminal suspect.

Murray has yet to speak publicly since Jackson's death. Police towed his car from Jackson's home hours after the entertainer died and said later that it could contain medication or other evidence. Coroner's officials also said Jackson had been taking prescription medication, but declined to elaborate.

A lawyer at a Houston firm, William M. Stradley, confirmed that Murray had hired his firm and said one of its partners was to have met yesterday with Los Angeles police. Stradley said Murray accompanied Michael Jackson to the hospital.

"He was there from the beginning, and he's been cooperating with police from the very beginning," Stradley said. "Dr. Murray has never left L.A. since Mr. Jackson's death, and he remains there."

Murray lives in Las Vegas, but apparently left his practice and moved in with Jackson about two weeks ago.

The promoter of the series of London concerts that Jackson was to begin next month has said Jackson personally insisted Murray be on the payroll.