Micheal Jackson died in 2009 due to a drug overdose after being administered two months of nightly propofol infusions by his physician.

Charles Czeisler is an American physicist and sleep researcher who graduated from Harvard College.

Czeisler devoted 40 years of his life to his sleep research and returned to Harvard as a teacher.

The sleep consultant was called to testify at Jackson’s wrongful death trial.

According to Czeisler, Propofol's sleep was not REM sleep even if the patient woke up feeling refreshed.

If Jackson had not overdosed on the surgical table, the lack of sleep would have killed him days later.

Czeisler mentioned symptoms people suffer from sleep deprivation experience, and reports about Jackson’s behavior seemed similar.

Jackson’s death was caused by excess Propofol in his system.

His physician, Conrad Murray, was sentenced to four years in prison but only served two years before his release.