Just before 3pm on a scorching August day in 2013 Chris Lane, a good-looking athlete from Melbourne, set off for a jog along Country Club Road in the southern Oklahoma city of Duncan.
Lane, 22, had a baseball scholarship at Oklahoma's East Central University and was visiting girlfriend Sarah Harper at her home in the rural city of 23,000.
As Lane approached an intersection in an affluent area of Duncan a bullet from a .22 calibre revolver was fired into the Australian's back.
The bullet collapsed both lungs, fractured two ribs and tore through his aorta and pulmonary artery.
Lane collapsed on the side of the road.
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A 911 phone call made by a frightened Duncan local, Joyce Smith, who saw Lane covered in blood gives insight into the terrible last seven minutes of Lane's life.
On Monday (Tuesday AEST) Chancey Luna, the boy prosecutors allege pulled the trigger that ended Lane's promising life will be escorted by sheriffs into Duncan's Stephens County courthouse for his first-degree murder trial.
Luna was 16 when he allegedly murdered Lane.
If found guilty he faces life in prison without the prospect of parole.
There are many theories in Duncan why Lane was shot.
"They wanted to be Billy Bob Badasses," Duncan police chief Danny Ford told AAP in the days after the shooting.
"They" are Luna and his two teenage mates, James Edwards who was 15 at the time of Lane's death, and Michael Jones, then 17.
Chief Ford said one of the boys admitted, "We were bored and didn't have anything to do, so we decided to kill somebody".
Edwards has become a prosecution witness and is expected to testify at the trial, which could last 10 days.
Edwards had a murder charge replaced by an accessory count.
In evidence at a preliminary hearing last year Edwards said Jones was driving a Ford Focus, he was in the front passenger seat rolling a joint and Luna was in the back seat.
Edwards said they saw a man jogging on the side of the road, the car accelerated and veered near the jogger and to his surprise a gun was fired from the back seat.
"Who shot the gun?" assistant district attorney Leah Edwards asked.
"Mr Luna," Edwards replied.
Edwards testified Luna later handed Jones the gun and said, "I thought there were supposed to be blanks in the gun," and Jones replied, "Me, too".
Luna's lawyers, cousins Jim and Howard Berry, told reporters Edwards' evidence pointed to an accidental shooting.
Last month Jones entered a guilty plea to second degree murder and was sentenced to life with the possibility of parole after 38 years.
A fourth defendant, Oddesse Barnes, 23, who was given the handgun after the shooting, pleaded guilty to accessory to murder and is eligible for release in 12 years.
Edwards hasn't been sentenced.
Lane's death shocked Duncan and the Berrys fear Luna will not get an impartial jury.
About 400 potential jurors have been summoned for jury duty, with selection for Luna's trial possibly taking four days.
