Jury selection began on Friday for the trial of a U.S. Army sergeant who has been accused of killings of innocent people in Afghanistan.

Calvin Gibbs, 26, of Billings, Montana, was charged with the murder of unarmed civilians and taking body parts to use as war trophies. Gibbs has been accused of being the ringleader of a killing squad that terrorized and killed innocent Afghans in Afghanistan’s Kandahar province.

Attorneys are scheduled to make their opening arguments on Monday.

Gibbs, an ex-staff sergeant in the Fifth Brigade of the U.S. Army’s Second Division, is one of the five soldiers, thought to be the ringleader of the pack, that is facing charges for the killings of innocent Afghan’s for fun, during a decade of war.

As reported by Reuters, Pentagon officials have said the misconduct exposed by the case, which began as a probe into hashish use within Gibbs' unit, had damaged America's image around the globe.

Army spokesman Major Christopher Ophardt told Reuters that about 30 witnesses are expected to testify during the court-material, slated to run at least through next week at Joint Base Lewis-McChord near Tacoma, Washington.

Specialist Jeremy Morlock, who was described as Gibbs’ right hand man, who was sentenced in March to 24 years in prison after pleading guilty to three counts of murder in the same killings Gibbs is accused for, is the chief prosecution witness that is expected to testify against Gibbs.

Morlock has already testified against Gibbs in July as part of the plea deal he reached with prosecutors, reported Reuters.

Gibbs has 5 charges against him, three counts of premeditated murder, cutting fingers off dead bodies and using them as trophies, and the beating of a fellow soldier. If he is convicted of all charges then he will face life in prison without any possibility of parole. However, Gibbs has pleaded not guilty to all of the criminal charges that the Army filed against him.