Demonstrators stand outside the courthouse during Dr. Conrad Murray's trial in the death of pop star Michael Jackson in Los Angeles September 28, 2011.[Photo/Agencies]

Witnesses on day two of the Michael Jackson death trial told of a panic-stricken doctor and the pop star's children crying in disbelief with their father lying unresponsive on his bedroom floor, mouth agape and eyes wide open.

Faheem Muhammad, the ex-chief of Jackson's security team, testified on Wednesday that Jackson's oldest children reacted in horror when they saw their father's lifeless body.

Another witness said Dr. Conrad Murray, who is charged with involuntary manslaughter in the death, telephoned the singer's assistant before calling an ambulance and may have sought to hide evidence of drug use.

Prosecutors claim Murray not only caused Jackson's death by giving him the powerful anesthetic propofol as a sleep aid, along with other sedatives but that the physician also was negligent in his care of the "Thriller" singer and failed to get timely medical assistance.

Murray admitted giving Jackson propofol -- the principal cause of his death -- but his defense attorneys claim Jackson administered more propofol to himself, leading to an overdose. Murray faces up to four years in prison if convicted.

Wednesday's most dramatic testimony came from Muhammad, who told of a panicked call from Murray that brought the security chief rushing to the singer's bedroom. There he saw Murray and another guard already in the room and Jackson's oldest children, Prince and Paris, taking in the frantic scene.

"Paris was on the ground balled-up crying and Prince, he was just standing there, he had a real shocked -- just slowly crying -- look on his face," Muhammad said.

Muhammad said that, around the same time, Murray asked himself and the other guard, "Does anybody know CPR?" Cardiopulmonary resuscitation is the common procedure to restart a heart in a person who has suffered cardiac arrest.

TIMELINE FOR HELP

In other testimony, prosecutors sought to draw a timeline between when Murray found Jackson unresponsive at 11:56 a.m. (2:56 p.m. EDT/1856 GMT) on June 25, 2009, and when the doctor finally sought help.

Initially, Murray called the singer's personal assistant, Michael Williams, at 12:13 p.m./1613 GMT with the message "Call me right away," rather than calling for an ambulance.

Williams testified that he called Murray back at 12:15 p.m., and was told Jackson had suffered "a bad reaction."

"When I hear a 'bad reaction,' I wouldn't think anything fatal, personally, and I wasn't asked to call 911," Williams said. He said Murray told him to get to Jackson's mansion immediately.

An ambulance was finally called at 12:20 p.m. and it was already there when Williams arrived at the Jackson mansion.

"It was real frantic. I got there when the gurney (carrying Jackson) was coming down" from the bedroom, Williams said.

The assistant said that at the hospital where Jackson was later pronounced dead, Murray made a request that seemed strange. "He said, 'There's some cream in Michael's room that he wouldn't want the world to know about,' and he requested that I or someone would give him a ride back to the house, so that he could get the cream," said Williams.

Prosecutors have suggested Murray probably wanted to return there to remove evidence of the drugs that he had given Jackson before he died.

Earlier on Wednesday, a lawyer who drafted Murray's contract to provide medical services for Jackson said the doctor had assured her multiple times in the days before his death that the singer's health was good.

"Dr. Murray told me repeatedly that Michael Jackson was perfectly healthy, in excellent condition," Los Angeles attorney Kathy Jorrie said on the witness stand.