Another chapter has been written in the senseless US drive-by shooting murder of Australian baseball player Chris Lane.
James Edwards Jr - who was 15 when Lane was gunned down while jogging along a Duncan, Oklahoma, residential street in 2013 - entered a guilty plea on Wednesday to accessory to murder.
Edwards Jr, who turned 18 last week and became a prosecution witness, faces between five and 45 years in jail when he is sentenced next June.
Judge Ken Graham placed some of Edwards Jr's destiny in the teenagers' own hands.
Edwards Jr will be held in a young inmate's program at an adult prison until the June 14 sentencing.
If he behaves, he might receive a discounted sentence.
Lane's father Peter, mother Donna, sisters, friends and team-mates have endured an agonising time as four accused went through the Oklahoma court system.
"Justice is finally coming through," the victim witness assistant on the case, Amy Hall, told AAP after Edwards Jr's plea.
On August 16, 2013, Edwards Jr was rolling a joint in the front seat of a Ford Focus driven by 17-year-old friend Michael Jones, with another friend, 16-year-old Chancey Luna, in the backseat.
Edwards Jr testified how Luna randomly selected 22-year-old Lane and shot him in the back with a .22 calibre revolver.
Luna was sentenced earlier this year to life in prison without the possibility of parole.
Jones entered a guilty plea to second-degree murder and was sentenced to life, but could be eligible for release after 38 years.
Oddesse Barnes, who was not in the car but helped hide the gun, will be eligible for release in 12 years for an accessory conviction.
Luna's mother, Jennifer, said her son's lawyers were working on an appeal.
Ms Luna said she was disappointed with what she described as the lenient treatment of Edwards Jr, while her son, now 18, faces the prospect of never spending a second of his life outside jail.
"I'm pretty upset about it," Ms Luna said.
"It's not right or fair."
Melbourne-raised Lane had a baseball sports scholarship with Oklahoma's East Central University and was visiting his girlfriend, Sarah Harper, in Duncan when he was shot.
