Dr. Conrad Murray pleaded not guilty to involuntary manslaughter in the death of Michael Jackson on Tuesday, setting up a high-profile trial in which prosecutors will try to prove it was his gross negligence that killed the legendary singer.

Katherine Jackson and her son Randy were among family members that attended the arraignment hearing at Los Angeles Superior Court.

If convicted, Murray could face a maximum of four years in prison. His medical license has been suspended pending the outcome of the trial. If found guilty, Murray will likely never practice medicine again.

Murray has been the focal point of an investigation since Jackson died June 25, 2009, at age 50. Murray acknowledged that he administered the hospital anesthetic propofol and other sedatives as Jackson, a chronic insomniac, struggled to sleep.