Michael Jackson's doctor pleaded not guilty to involuntary manslaughter here Monday in connection with the pop superstar's sudden death last year from a lethal cocktail of prescription drugs. Conrad Murray, 56, appeared before a packed courtroom to deny a single charge of causing Jackson's death, the culmination of a painstaking seven-month probe which involved local and federal investigators. Murray's defense attorney Ed Chernoff entered the not guilty plea before the physician was ordered to surrender his passport and posted bail of $75,000 ahead of a hearing on April 5. Murray, the last person to see Jackson alive, has admitted administering drugs to the singer to help him sleep shortly before his death at a rented mansion in Los Angeles on June 25 last year. The doctor, who could face up to four years in prison if convicted, has acknowledged giving the anesthetic propofol to Jackson following the singer's "repeated demands/requests for the drug. Propofol is a potent anesthetic used to render patients unconscious before major surgery. Medical experts say it should only be used and administered by trained staff under hospital conditions. The Los Angeles County's coroner's office has blamed Jackson's death on "acute propofol intoxication. Judge Keith Schwartz said that while Murray was free to continue to practice, he was barred from prescribing propofol. "You may not under any circumstances use any anesthetic agent, particularly propofol, Schwartz said. "You cannot have it, you cannot prescribe it. "You are not to give any heavy sedatives like that. I don't want you sedating people. Murray's attorney meanwhile said he was "in good spirits. "He's looking forward to getting back to his patients, Chernoff said, confirming that the physician had been a regular visitor to Jackson's tomb since his death. "They were friends and he's personally sad, Chernoff revealed. "This has been a nightmare for him for many different reasons, one of which is that he lost a friend. He has been visiting the grave regularly. Monday's long-anticipated hearing took place in a circus-like atmosphere, with members of Jackson's family, including parents Katherine and Joe, present in court to face the man accused of killing "the King of Pop. Outside, Jackson devotees gathered to protest the involuntary manslaughter charge, saying Murray should have been charged with murder. "We want justice for Michael, said Michelle Perell, 26. "He (Murray) should be charged with first or second degree murder ... He killed the most beautiful person in the world. Other fans brandished banners which read: "The World Wants Justice for Michael and "Conrad Murray is a Murderer: Arrest him in handcuffs. Brian Oxman, a lawyer for Jackson's family, criticized the involuntary manslaughter charge, saying it was a "slap on the wrist. "There's great disappointment here, Oxman told People magazine, saying that Murray "should've been charged with a higher degree of responsibility. What he did was reckless. The manslaughter case against Murray was built during a prolonged investigation which saw raids on the doctor's offices in Houston and Las Vegas. According to affidavits unsealed during the investigation, Murray told investigators he had feared Jackson was becoming addicted to propofol and that he was trying to wean him off the drug at the time of his death. Murray, who had been hired by Jackson in April 2009 as the singer prepared for a grueling series of comeback concerts in London, allegedly told investigators he left the singer alone for a few minutes before returning to find he was not breathing. Murray insisted he didn't give Jackson anything that should have caused the singer's death. In a one-minute video posted on YouTube in August, Murray assured his patients that he had told the truth and said he had "faith the truth will prevail. Jackson's mother Katherine however expressed her belief that Murray was guilty following Monday's hearing. "Nobody was there but him, she told ABC7 television. "He's guilty. He's just trying to save his own behind.
