Opening statements at the involuntary manslaughter trial of Dr. Conrad Murray, pop star Michael Jackson’s personal physician, began on Tuesday with widely differing accounts of the day when the ‘Thriller’ singer died.

Prosecutor David Walgren alleged that Murray recklessly gave Jackson excessive levels of the surgical anesthetic propofol, which led to the singer’s death on June 25, 2009.

The prosecutors said the drug was misused as a sleep aid.

Walgren said Murray bought large quantities of the drug – about 4 gallons - in the months ahead of the trial.

Walgren also played audio of Jackson slurring his speech, where the singer said he wanted to build the world’s largest children’s hospital. That recording, found on Murray’s cell phone, meant the doctor was aware of Jackson’s condition and kept giving Jackson the drug anyway.

Defense attorney Ed Chernoff said Jackson died due to his own actions when he swallowed several lorazepam pills – enough to put 6 people to sleep - on the day he died. In addition, Jackson gave himself propofol, Chernoff said, instantly killing him.

Murray has pleaded not guilty to the charge.