CBS News has also learned that when Jackson would have even minor cosmetic procedures such as Botox, he would take Demerol, a narcotic painkiller not normally prescribed for such a procedure.
Frank Dileo was recently rehired as Jackson's manager.
"There were a couple of days where you say, 'Mike, are you alright? Are you taking anything?'" Dileo recalls saying to Jackson.
Dileo says Jackson's reply was: "Well no, why? What would make you think that? Don't ask me that. I have kids, I'm not doing that."
"So what are you going to say, he's a grown man," Dileo said.
The LAPD has now executed three search warrants and a law enforcement source says that one of the drugs investigators removed from Jackson's house was Diprivan, a powerful sedative used as anesthesia during surgery. Jackson is said to have sought out the drug in recent months to help him sleep.
Anesthesiologist Paul Wischmeyer studies Diprivan abuse.
"If you make a small error in how much you give yourself, even one cc's difference, you go from being high to being dead," Wischmeyer said.
We should know more about which drugs, if any, caused Jackson's death when the toxicology report comes back in a couple of weeks. Meanwhile, fans are gathering at Forest Lawn Cemetery, where there is speculation the burial will take place.