Questions Remain in Jackson's Death

Michael Jackson was never far from the spotlight when he was alive, but now the whereabouts of his body are a growing mystery, reports CBS News correspondent Ben Tracy.

The casket was on display at the memorial service Tuesday, but the Jackson family is now closely guarding its location and does not yet want the public to know when or where Michael Jackson will be laid to rest, opening the possibility that it could still be at Neverland, the singer's famed ranch.

Meanwhile, the coroner's office is running tests on portions of his brain, hoping to determine whether he had any underlying condition, such as a tumor, that contributed to his death.

"This is being done to rule out disease and ultimately the toxicology report will tell us definitively as to why Mr. Jackson died," said Dr. Lawrence Kobilinsky, with the John Jay College of Criminal Justice.

The death certificate lists the cause of death as "deferred." The toxicology report may show whether prescription painkillers played any role in Jackson's death. But experts say Diprivan, a powerful anesthesia drug, allegedly used as a sleep aid by the singer, is often hard to detect on routine toxicology tests.

"You have to send urine and potentially blood and potentially hair to very specialized laboratories," said Dr. Paul Wischmeyer, a Diprivan expert.

The shrine to Jackson at his parents' home was dismantled today. Also Wednesday, the Web site TMZ.com, which first broke the news of Jackson's death, reports that the Jackson family gave investigators a list of doctors who may have been overprescribing medication for Michael Jackson. It reportedly includes Dr. Arnold Klein, Jackson's longtime dermatologist. On "Good Morning America," he said he is not one of the five doctors thought to be targeted by the investigation.

"I was not one of the doctors who participated in giving him overdoses of drugs or too much of anything," Klein said. "In fact, I was the one who limited everything, who stopped everything."

Meanwhile, a custody hearing for Jackson's three children will take place on Monday. It is not clear whether Debbie Rowe, Jackson's ex-wife, will fight Jackson's mother Catherine for custody.