Diane Dimond has been covering Michael Jackson news since 1993, and now the investigative journalist talks to ET from the site of his public memorial: The Staples Center in Los Angeles.

"Since 1993, I saw a marked decline in not only his behavior and temperament, but in his songs. They got dark after 1993. They got especially dark after 2003," she says, the latter being the year of the molestation charges of which he was acquitted.

Jackson died on June 25, and the coroner is waiting for the results of toxicology tests before announcing a cause of death.

"There have been reports that there are five doctors that the police are looking at," she says, referring to the names found on all the prescription drugs found in Michael's home. "Some of them are in Hollywood, but I know there was one in Miami."

Diane says it is best to wait for police to release the names before speculating on who might be a person of interest.