Los Angeles, California (CNN) -- Dr. Conrad Murray, personal physician to Michael Jackson, was charged Monday with involuntary manslaughter in connection with the pop star's death last summer.





A criminal complaint filed earlier in the day alleged that Murray "did unlawfully, and without malice, kill Michael Joseph Jackson."





Murray turned himself in shortly before 4 p.m. at a branch courthouse near Los Angeles International Airport. He pleaded not guilty during a brief hearing before Judge Keith L. Schwartz.





The judge set bail at $75,000, despite arguments from prosecutor David Walgren that Murray is a flight risk.





The judge refused to suspend Murray's medical license as a term of his bond, but he did order him not to use any anesthesia on patients.





"I don't want you sedating people," Schwartz told Murray.





Read the criminal complaint





The involuntary manslaughter charge means that Murray caused Jackson's death by acting "without due caution and circumspection."





If convicted, Murray would face a maximum four-year prison sentence, according to prosecutors.





More on involuntary manslaughter





Members of Michael Jackson's family -- including his parents Joe and Katherine Jackson, sister La Toya Jackson, and brothers Jackie, Jermaine, Randy and Tito Jackson -- attended the hearing.





"Not enough," Jermaine Jackson said when asked what he thought of the charge.





"I don't like what happened," Joe Jackson said as he left the courthouse.





La Toya Jackson later issued a statement through a publicist.





"Michael was murdered and although he died at the hands of Dr. Conrad Murray, I believe Dr. Murray was a part of a much larger plan," her statement said. "There are other individuals involved and I will not rest and I will continue to fight until all of the proper individuals are brought forth and justice is served."





Her statement did not elaborate on what she meant in her reference to "a much larger plan."





Murray traveled to Los Angeles at the end of January from his home in Houston, Texas, in expectation of possible charges, his lawyer said.





He used part of his time last week to visit the pop star's resting place in the Forest Lawn Memorial Park in Glendale, California.





Murray, a cardiologist, was hired as Jackson's personal physician last spring as the singer prepared for comeback concerts in London, England.





The doctor told Los Angeles police that he was with Jackson at his $100,000-a-month rented Holmby Hills mansion through the early morning hours of June 25, 2009, in an effort to help the pop star fall asleep, according to a police affidavit.





He administered sleep aids, and after Jackson finally began sleeping in the late morning hours, Murray said, he left the bedroom for "about two minutes maximum," the affidavit says.





"Upon his return, Murray noticed that Jackson was no longer breathing," it says.





The doctor stayed with Jackson as an ambulance rushed him to UCLA Medical Center.





Efforts at CPR proved fruitless, and Jackson was pronounced dead at 2:26 p.m.





The Los Angeles County coroner ruled Jackson's death a homicide, resulting from a combination of drugs, primarily propofol and lorazepam.





The coroner's statement said Jackson died from "acute propofol intoxication," but there were "other conditions contributing to death: benzodiazepine effect." Lorazepam and two other drugs Murray said he used are benzodiazepines.





The doctor told investigators he had given Jackson three anti-anxiety drugs to help him sleep in the hours before he stopped breathing, a police affidavit said.





Murray had been treating Jackson for insomnia for six weeks at the time of the singer's death. The doctor told investigators he gave Jackson 50 milligrams of propofol, the generic name for Diprivan, diluted with the anesthetic lidocaine every night via an intravenous drip.





The doctor told police he was worried that Jackson was becoming addicted to the drug and tried to wean him off it.





During the two nights before Jackson's death, Murray said, he put together combinations of other drugs that succeeded in
What was the cause of Jackson's death? What did Jermaine Jackson say? What year did the singer pass away?
homicide, resulting from a combination of drugs, primarily propofol and lorazepam. "Not enough," 2009,
question: What was the cause of Jackson's death?, answer: homicide, resulting from a combination of drugs, primarily propofol and lorazepam. | question: What did Jermaine Jackson say?, answer: "Not enough," | question: What year did the singer pass away?, answer: 2009,