Michael Jackson's doctor, Conrad Murray, waited at least 21 minutes to call an ambulance and tried to cover up evidence of how the singer died, a court heard today in Los Angeles.

Today marks the start of the preliminary hearing in front of Los Angeles Superior Court Judge Michael Pastor to see if there's enough evidence to start a trial against Dr. Conrad Murray who has been charged with involuntary manslaughter.

Prosecuter David Walgren said Murray tried to hide that he had given propofol to Jackson, and ordered a bodyguard to collect incriminating items before paramedics were called. 

Watch HLN's preview about the preliminary hearing for Dr. Conrad Murray below: