Tune in to HLN for full coverage and analysis of the Conrad Murray trial and watch live, as it happens, on CNN.com/live and CNN's mobile apps.

Los Angeles (CNN) -- The trial of Conrad Murray resumes Wednesday with an anesthesiology expert who is likely the last witness before the prosecution rests its direct case.

Murray is on trial for involuntary manslaughter in the 2009 death of Michael Jackson.

He has pleaded not guilty.

Testimony was suspended last Thursday to enable his lawyers to study a new lab test and allow the prosecution's anesthesiology expert, Steven Shafer, to attend a medical convention. It was delayed again after a death in the expert's family.

The judge indicated if Shafer's testimony is completed Wednesday, court would recess a day later to allow the defense to prepare before presenting its case Friday.

Prosecutors are nearing a conclusion to their direct presentation, but rebuttal witnesses could be called next week after the defense rests its case.

Prosecutors allege that Murray, who was Jackson's personal doctor as he prepared for planned comeback concerts, is criminally responsible for the singer's death because of medical negligence and his reckless use of the surgical anesthetic propofol to help him sleep.

Murray faces a maximum sentence of four years if convicted of involuntary manslaughter, but a new California law could mean the doctor would never see the inside of a state prison cell.

The law, intended to reduce state prison overcrowding, provides for most nonviolent offenders with no prior record to be kept in county jails.

A four-year sentence could become two years if Murray is ordered to serve his time in the Los Angeles County jail, according to sheriff's spokeswoman Nicole Nishida.

The Los Angeles jail is under court order to reduce overcrowding, which means many nonviolent first time offenders are allowed to serve the bulk of their time under supervised house arrest.

A conviction, however, would likely trigger the revocation of Murray's medical licenses in California, Texas and Nevada.

The trial, in its fourth week, is still expected to conclude with the start of jury deliberations next week.

Shafer is crucial to the state's effort to prove Jackson's death was caused by the doctor's gross negligence in using propofol to help the pop icon sleep.