Reports of Murray's looming manslaughter case followed a painstaking and prolonged police investigation.

Under California law, involuntary manslaughter -- unintentionally causing death through negligence, carelessness or a misdemeanor -- is punishable by up to four years in prison.

Murray, 56, has acknowledged that he administered the powerful anesthetic propofol to Jackson only after trying many other medications to help him sleep following the singer's "repeated demands/requests" for the drug.

Propofol is a powerful anesthetic used to render patients unconscious before major surgery. Medical experts say it should only be used and administered by trained staff under hospital conditions.

Unsealed court documents that included a review of toxicology results found that Jackson died from "lethal levels of propofol."